Trend In Relative Humidity Research Articles

Forecasting Trends in Relative Humidity in Iraq (Study in Climate Geography)

The research aims to predict and determine the trend in relative humidity rates (%) in Iraq, for four months (October, January, April, July), as the percentage of water in the atmosphere does not exceed (0.01%) of the hydrosphere at any moment. Despite this, it is an important element in the weather and plays a major role in the formation of clouds, fog, and dew. He is responsible for all major weather events, such as hurricanes and other weather disturbances. To understand the nature of the behavior of relative humidity, its trend, fluctuations, and future changes in time and space, statistical models were designedm(SARIMA) based on the Box–Jenkins method in the time series forecasting method for the period (2023-2037), for the following stations (Kirkuk - Baghdad - Al-Hayy - Samawah - Nasiriyah - Basra) and relying on the base years from (1970 - 2022), and the research adopted the use of The algorithm drawn up by two researchers (BJ 1976), used the autoregressive model and the seasonal integration moving average, which is symbolized by the symbol (p, d, q) (P, D, Q) SARIMA, which is called the seasonal multiplier model.

The impact of changes in temperature trends on relative humidity trends in the city of Jeddah in Kingdom of Saudi Arabia for the period from 1985 to 2022 AD

The impact of changes in temperature trends on relative humidity trends in the city of Jeddah in Kingdom of Saudi Arabia for the period from 1985 to 2022 AD

Water temperature and energy balance of floating photovoltaic construction water area—field study and modelling

Floating photovoltaics (FPV) are an emerging renewable energy technology. Although they have received extensive attention in recent years, understanding of their environmental impacts is limited. To address this knowledge gap, we measured water temperature and meteorological parameters for six months under FPV arrays and in the control open water site and constructed a numerical model reflecting the water energy balance. Our results showed that FPV arrays caused diurnal variation in water temperature and microclimate. Specifically, we found that FPV had a cooling effect on their host waterbody during the daytime and a heat preservation effect at night, reducing diurnal variation. The diel oscillation of water temperature below FPV panels lagged behind that of open waters by approximately two hours. The microclimate conditions below FPV panels also changed, with wind speed decreasing by 70%, air temperature increasing during the daytime (averaging +2.01°C) and decreasing at night (averaging −1.27°C). Notably, the trend in relative humidity was the opposite (−3.72%, +14.43%). Correlation analysis showed that the degree of water temperature affected by FPV was related to local climate conditions. The numerical model could capture the energy balance characteristics with a correlation coefficient of 0.80 between the simulated and actual data. The shortwave radiation and latent heat flux below FPV panels was significantly reduced, and the longwave radiation emitted by FPV panels became one of the heat sources during the daytime. The combined variations of these factors dominated the water energy balance below FPV panels. The measured data and simulation results serve as a foundation for evaluating the impact of FPV systems on water temperature, energy budget, and aquatic environment, which would also provide a more comprehensive understanding of FPV systems.

Evolution behavior of adhesion force with continually changed relative humidity revealed on AFM

ABSTRACT Adhesion forces on various surfaces with different hydrophilicity were measured by atomic force microscopy in the force-volume mode and at a location to study the relative humidity (RH) dependence. With an increasing-stable-decreasing trend in RH, the force in the force-volume mode usually exhibits a constant-increase-constant-decrease-constant variation. Surfaces with partial or complete hydrophobicity exhibited a much larger increase compared to a hydrophilic one. However, the behavior on some surfaces was distorted due to a decrease at high stable RHs. Contrastively, the behavior at a location could also display the same behavior. Both gradual and sudden changes were observed at a single location as RH changed. At high stable RHs, the force displayed complex behaviors, indicating unique characteristics at each location. Therefore, the measurement at a location is not suitable to study the RH dependence. Specially, the force measured on silica in the force-volume mode has the mentioned behavior. However, the force at a location can remain stable, gradually/sharply increase or decrease, and suddenly jump or drop with RH. These observations are attributed to the evolution of a water bridge, which is largely influenced by thin-film flow. The findings provide deeper insights into adhesion mechanisms at different RHs.

Analyzing temperature, humidity, and precipitation trends in six regions of Thailand using innovative trend analysis

The change of temperature and weather parameters is a major concern affecting sustainable development and impacting various sectors, such as agriculture, tourism, and industry. Changing weather patterns and their impact on water resources are important climatic factors that society is facing. In Thailand, climatological features such as ambient temperature, relative humidity, and precipitation play a substantial role in affecting extreme weather events, which cause damage to the economy, agriculture, tourism, and livelihood of people. To investigate recent serious changes in annual trends of temperature, relative humidity, and precipitation in Thailand, this study used the Mann–Kendall (MK) test and innovative trend analysis (ITA) methods. The MK test showed that all six regions had an upward trend in temperature and humidity index (humidex, how hot the weather feels to the average person), while relative humidity and precipitation showed both upward and downward trends across different regions. The ITA method further confirmed the upward trend in temperature and humidex and showed that most data points fell above the 1:1 line. However, the upward trend in most variables was not significant at the 5% level. The southern and eastern regions showed a significant upward trend in relative humidity and humidex at a 5% level of significance according to the MK test. The output of this study can help in the understanding of weather variations and predict future situations and can be used for adaptation strategies.

Assessment of climate change in different regions of Karnataka state

At the regional level, climate change has significant influences on crop productivity and food security. A climate change study was carried out using different parametric indices like rainfall attributes, temperature, and humidity from 58 years of climatic data (1964-2017) in Karnataka. The climatic period was divided into the Pre-climate change period- P1 (1964-1990) and the climate change period- P2 (1991-2017) with 27 years. The result shows annual rainfall and rainy days were increased in South Interior Karnataka (SIK) and Malnad regions and reduced in North Interior Karnataka (NIK) and Coastal regions. Dakshina Kannada, Yadgir, Kalabarugi, Udupi and Kodagu districts showed a significant reduction in receiving rainfall and an increase in Shivamogga, Hassan, Kolar and Chitradurga districts from the P1 to P2 period. NIK and SIK regions are highly prone to drought vulnerability compared to Malnad and Coastal regions. The occurrence of droughts wasincreasing,the temperature trend is increased and the relative humidity trend is decreasing in the P2 period. Assessment of climate variability in P1 and P2 helps to adopt preciseuse of water, nutrient and different crop-specific management in different zones of Karnataka.

Understanding climate change dynamics in the Godavari middle sub-basin using parametric and non-parametric models

Climate change is considered a long-term change in precipitation, temperature and other meteorological variables. The pattern of meteorological variables is changing due to anthropogenic activities globally. Climate change has posed threat to natural and human systems. Thus, assessing and forecasting climate variability have become imperative for making resources sustainable and society resilient. This study examined trend and forecasted climate change using parametric and non-parametric methods in the Godavari Middle Sub-basin, India. Mann-Kendall and Sen's slope methods were utilized to analyze trend and magnitude of meteorological variables such as rainfall, maximum and minimum temperature, mean wind speed, mean evaporation and relative humidity. Forecasting of meteorological variables was carried out using the autoregressive integrated moving average (ARIMA) and seasonal autoregressive integrated moving average (SARIMA) models. Increasing trend in maximum and minimum temperature was observed at various level of significance. Decreasing trend was observed in mean evaporation at 0.05 level of significance. Decreasing trend in wind speed was also recorded in the sub-basin. February, March, April, June, October and December have shown increasing trend in relative humidity. Total monthly rainfall has shown decreasing trend in the south-eastern part of the sub-basin. Forecast of meteorological variables have also shown decrease in rainfall, increase in maximum and minimum temperature during 2017–2027 creating the sub-basin more prone to dry climate condition. Thus, a policy intervention-oriented climate action plan for lessening the impact of climate change is required in the sub-basin.

On the Precursor Environments to Mountain Lee Wave Clouds in Central Iberia under CMIP6 Projections

Mountain lee waves present significant hazards to aviation, often inducing turbulence and aircraft icing. The current study focuses on understanding the potential impact of global climate change on the precursor environments to mountain lee wave cloud episodes over central Iberia. We examine the suitability of several Global Climate Models (GCMs) from CMIP6 in predicting these environments using the ERA5 reanalysis as a benchmark for performance. The dataset is divided into two periods: historical data (2001–2014) and projections for the SSP5–8.5 future climate scenario (2015–2100). The variations and trends in precursor environments between historical data and future climate scenarios are exposed, with a particular focus on the expansion of the Azores High towards the Iberian Peninsula, resulting in increased zonal winds throughout the Iberian Peninsula in the future. However, the increase in zonal wind is insufficient to modify the wind pattern, so future mountain lee wave cloud events will not vary significantly. The relative humidity trends reveal no significant changes. Moreover, the risk of icing precursor environments connected with mountain lee wave clouds is expected to decrease in the future, due to rising temperatures. Our results highlight that the EC-EARTH3 GCM reveals the closest alignment with ERA5 data, and statistically significant differences between the historical and future climate scenario periods are presented, making EC-EARTH3 a robust candidate for conducting future studies on the precursor environments to mountain lee wave cloud events.

Study on ambient temperature and humidity in the construction tunnel under the influence of ventilation and hot water gushing

The influx of hot water will intensify the detrimental effects of heat and humidity during the excavation of high geothermal tunnels. The spatiotemporal evolution of the ambient temperature-humidity field in the construction tunnel under the coupling action of ventilation and hot water is critical. Based on the theory of heat and mass transfer, a numerical model was developed to simulate the temperature and humidity conditions within a construction tunnel. The model considers the coupling effects of heat and moisture between airflow, hot water, and the surrounding rock. The distribution of temperature and humidity in the tunnel was analyzed, and the study investigated the influence mechanisms of ventilation volume (Va) and water gushing conditions on the ambient temperature and humidity in the construction tunnel. The main conclusions include: (1) During tunnel construction, the airflow temperature (Ta) and relative humidity (RH) varied as follows: heating and humidifying, constant humidity heating, and constant humidity cooling. (2) Altering the water temperature (Tw) will affect the distribution pattern of RH from the working face to the tunnel portal. Similarly, modifying the length of the ditch without the cover plate (Lc) will impact the distribution trend of Ta and RH. (3) When the Va affects the RH mainly through the airflow velocity rather than the evaporation coefficient, the linearity between the Va and RH is weak. Water volume and Tw both impact the humidity distribution by altering the amount of heat needed for evaporation. (4) Given the significance of the impact of individual factors on the temperature and humidity, it is advised that the Ta and RH be regulated by increasing the Va and decreasing the Lc, respectively. The research can give direction for temperature and humidity control in a tunnel where hot water gushes during construction.

A Climatological Survey of Corsica for Power System Analyses

Climate and climate change can impact present and future energy production and demand. In light of this issue, this paper conducts climatological analyses focused on the following meteorological quantities: shortwave downward irradiance (SDI), precipitation (Pr), relative humidity (RH), air temperature (Ta), 10 m wind speed (v10), and diurnal temperature range (DTR) for four locations in Corsica. The climate analyses of these atmospheric variables consist of three parts: (1) analysis of the historical trends; (2) correlation analysis; and (3) analysis of climate projections for the decades to come. It is observed that climate change is causing alterations in the trends of Pr, RH, Ta, v10, and DTR. The correlation analysis reveals a positive correlation for the Ta-SDI and v10-Pr pairs (both annually and seasonally), and a negative correlation for Ta-RH (annually and in summer). For the other variable pairs, the sign of the correlations varies depending on the time period and site considered. The trends in the projections from the multi-model ensemble simulations are consistent or inconsistent with each other depending on the time period (annual or seasonal) considered. The observed historical trends suggest that medium-term planning of the Corsican electric power system should already consider ongoing climate change. The correlation analysis provides insights into the combined effect of different atmospheric variables on electrical power systems (EPSs). Climate projections suggest studying long-term planning that is a compromise among the different (but equally likely) outputs of different climate models.

Spatiotemporal characterization of relative humidity trends and influence of climatic factors in Bangladesh

The frequency and intensity of climate change and resulting impacts are more prevalent in South Asian countries, particularly in Bangladesh. Relative humidity (RH) is a crucial aspect of climate, and higher RH variability has far-reaching impacts on human health, agriculture, environment, and infrastructure. While temperature and rainfall have gained much research attention, RH studies have received scant attention in the research literature. This study investigated the trends and variability of RH levels in Bangladesh and the influence of other meteorological factors over the past 40 years. Variabilities in the meteorological factors were identified by calculating descriptive statistics. Innovative trend analysis (ITA) and Mann-Kendall test (MK-test) methods were utilized to assess monthly, seasonal, and annual trends. The magnitude of temperature, rainfall, and windspeed influences on RH variability were identified using Pearson's correlation, Spearman rank correlation, and Kendall correlation model. Variability analysis showed higher spatial variations in RH levels across the country, and RH skewed negatively in all stations. Results reveal that daily, monthly, seasonal, and annual trends of RH exhibited positive trends in all stations, with an increasing rate of 0.083–0.53% per year in summer, 0.43–0.68% per year in winter, and 0.58–0.31% per year in the rainy season. Both ITA and MK-test provided consistent results, indicating no discrepancies in trend results. All three models indicate that temperature, rainfall, and windspeed have weak to moderate positive influences on changing RH levels in Bangladesh. The study will contribute to decision-making to improve crop yields, health outcomes, and infrastructure efficiency.

Influence of meteorological factors and air pollutants on bacterial concentration across two urban areas of the Sistan region of Iran

This study assesses relationships between meteorological factors and air pollutants with ambient bacterial concentration. In the two main cities of Sistan, Zabol and Zahak, airborne bacteria concentration was monitored using the settle plate method inside and outside household environments during dusty days and nights in summer, autumn, and winter in 2022. As context for the study, it was determined that air quality index (AQI) values >100 on most sampling days in Zabol (51.9%) and Zahak (70.4%), with higher values in summer than autumn and winter. The lowest and highest bacterial concentrations in outdoor air were observed at AQI < 50 (good) and AQI > 300 (hazardous), respectively, in both cities. Bacterial concentration showed a decreasing trend from summer to winter, which coincided with a decreasing trend of air pollutant indices, wind speed, and temperature in addition to an increasing trend of relative humidity. Temperature, relative humidity, and atmospheric pressure had negative correlations, while wind speed and air pollutant indices (PM10, PM2.5 and AQI) showed positive correlations and wind direction had no correlation with bacterial concentrations. The factors best related to bacterial concentrations were air quality indices (PM10, PM2.5 and AQI) in both cities, with the highest levels driven by dust storms in Sistan.

The understory microclimate in agroforestry now and in the future – a case study of Arabica coffee in its native range

Climate change is having a major impact on crop production and food security worldwide, and particularly so for smallholder farmers. As agroforestry is common with smallholder farmers, it is important to not only model the macroclimate, but also the microclimate that crops experience below the canopies. However, there are few high-resolution spatiotemporal climate projections for forest understories, because of constraints related to the lack of i) development of models for downscaling global climate projections, ii) high-resolution gridded datasets of environmental factors influencing microclimate, and iii) spatially replicated in-situ microclimate measurements. We focused on a landscape in southwestern Ethiopia where Arabica coffee originated, and, in the present day, is commonly grown as a shade crop. We first examined the relative contribution of in-situ field measurements vs. GIS-derived estimates of vegetation and topographic features in explaining in-situ microclimate. Second, we used a statistical downscaling approach to obtain past and future microclimate maps at 30-meter spatial resolution for the part of the landscape that is covered by trees. Predictive models using in-situ variables performed equal to models with GIS variables, indicating that remote sensing data might substitute for in-situ field measurements. Vegetation and topographic features were both important in explaining microclimatic variation. Our spatiotemporal projections of the microclimate indicate that coffee farming might have to relocate to higher altitudes due to increasing temperatures, that vegetation might buffer the macroclimate at middle altitudes to some extent, and that decreasing trends in relative humidity at the beginning of the wet season might become problematic for coffee production. Taken together, our findings demonstrate that we can rely on remote sensing data to create microclimate maps in landscapes where in-situ field measurements are challenging, and we suggest how these microclimate projections can be used as a tool to promote climate-resilient agriculture at the local and landscape levels.

Spatio-Temporal Trend Analysis of Reference Evapotranspiration in Central Luzon, Philippines

Understanding trends in reference evapotranspiration (ETₒ) and their influencing factors is crucial for calculations of irrigation requirements and water management. Meteorological data in Central Luzon (1985–2019) were used to estimate ETₒ using the FAO Penman-Monteith method. Spatial and temporal ETₒ trends were analyzed using the Mann-Kendall test and Sen’s slope estimator. Correlation and sensitivity analyses were conducted to analyze the impact of weather variables on ETₒ. Positive correlations were observed for maximum temperature, solar radiation, and wind speed whereas negative correlations were observed for relative humidity and minimum temperature. In general, ETₒ was statistically dependent and most sensitive to solar radiation, maximum temperature, and relative humidity. ETₒ in the stations surrounded by mountains was consistently lower than the stations in the agricultural areas by 197 and 207 mm for the dry season and annual basis, respectively. The increasing trends with a magnitude of 3.98 mm/yr in annual ETₒ were caused by the rising trend in solar radiation and maximum temperature and a decreasing trend in relative humidity. The decreasing ETₒ trend (–2.6 to –4.63 mm/yr) predominant in the study area was mainly attributed to the decreasing trend of solar radiation and wind speed. Areas with increasing ETₒ trends indicate the need for supplemental irrigation. Decreasing ETₒ trends may indicate climate change, land-use change, or human-related factors.

Direct observation of Earth’s spectral long-wave feedback parameter

The spectral long-wave feedback parameter represents how Earth’s outgoing long-wave radiation adjusts to temperature changes and directly impacts Earth’s climate sensitivity. Most research so far has focused on the spectral integral of the feedback parameter. Spectrally resolving the feedback parameter permits inferring information about the vertical distribution of long-wave feedbacks, thus gaining a better understanding of the underlying processes. However, investigations of the spectral long-wave feedback parameter have so far been limited mostly to model studies. Here we show that it is possible to directly observe the global mean all-sky spectral long-wave feedback parameter using satellite observations of seasonal and interannual variability. We find that spectral bands subject to strong water-vapour absorption exhibit a substantial stabilizing net feedback. We demonstrate that part of this stabilizing feedback is caused by the change of relative humidity with warming, the radiative fingerprints of which can be directly observed. Therefore, our findings emphasize the importance of better understanding processes affecting the present distribution and future trends in relative humidity. This observational constraint on the spectral long-wave feedback parameter can be used to evaluate the representation of long-wave feedbacks in global climate models and to better constrain Earth’s climate sensitivity.

Thermodynamics of Evaporation from the Ocean Surface

Adopted by the Intergovernmental Oceanographic Commission (IOC) of UNESCO in 2010 and the International Union of Geodesy and Geophysics (IUGG) in 2011, the Thermodynamic Equation of Seawater 2010 (TEOS-10) is the current geophysical standard for the thermodynamic properties of humid air, seawater and ice. TEOS-10 equations for evaporation and sublimation enthalpies are derived mathematically from the thermodynamic potential of a »sea air« model, denoting a multi-phase equilibrium composite of the geophysical aqueous mixtures. To estimating evaporation rates from the ocean, Dalton equations in various versions are implemented in numerical climate models. Some of those equations appear to be biased on climatic time scales if compared with proper thermodynamic driving forces. Such equations may lead to a spurious amplification of the hydrological cycle and an implied effect of cooling oceans. As an unbiased alternative, Dalton equations are proposed in terms of TEOS-10 relative fugacity (RF) or its conventional relative humidity (RH) approximations. With respect to RH uncertainties or trends, the substantial sensitivity of the evaporation flux may be estimated to be as much as 5 W m−2 per 1 %rh. Within a maximum error of only 0.04 %rh, sea-surface RF may be approximated in terms of dew-point or frost-point temperatures using a simple formula.

Investigation of innovative trend approaches (ITA with significance test and IPTA) comparing to the classical trend method of monthly and annual hydrometeorological variables: a case study of Ankara region, Turkey

Abstract The difficulty of monitoring hydrometeorological trends remains relevant because of the importance of climate change. In this study, innovative polygon trend analysis (IPTA), new graphical methods, have recently been presented, Mann-Kendall and innovative trend analysis (ITA) with significance tests are employed at monthly and annual hydrometeorological data for Ankara province in Turkey. Finally, sequential Mann-Kendall (SQ-MK), CUSUM, and standard normal homogeneity test (SNHT) are applied to detect any abrupt changes in annual time series. The results indicate that ITA with significance test, IPTA, and MK capture precipitation trends in 83, 94, and 0.2% of all months (3 stations × 12 months), temperature trends in 86, 75, and 22% of all months, relative humidity trends in 80, 80, and 30% of all months, and evapotranspiration series in 91, 80, and 47% of all months. These findings suggest that the ITA with significance test and IPTA are more sensitive than the MK test, with the precipitation series being the most sensitive and the evapotranspiration series being the least sensitive. SQ-MK, CUSUM, and SNHT tests on station 17664 were successful in detecting a change in annual evapotranspiration in 2005. The annual total evaporation series have been rising since 2005, according to the SQ-MK test.

Changes and determining factors of crop evapotranspiration derived from satellite-based dual crop coefficients in North China Plain

Evaluating actual crop evapotranspiration (ETc) variations and their determining factors under changing climates is crucial for agricultural irrigation management and crop productivity improvement in non-humid regions. This study analyzed the spatiotemporal characteristics and detected the determining factors of ETc for winter wheat and summer maize rotation system from 2000 to 2017 in the North China Plain (NCP), by combining the FAO-56 dual crop coefficient approach with remotely sensed vegetation indices (VIs). The results indicated that daily air temperature increased in varying degrees while wind speed and sunshine hours decreased slightly during the growing season of winter wheat and summer maize over the study period. The trends of relative humidity and effective precipitation varied in crop growing seasons. Based on the validated relationship of dual crop coefficients and VIs, the estimated multi-year average ETc of winter wheat (370.29 ± 31.28 mm) was much higher than summer maize (281.85 ± 20.14 mm), and the rotation cycle was 652.43 ± 27.67 mm. Annual ETc of winter wheat and the rotation cycle increased by 2.96 mm a−1 and 1.77 mm a−1, respectively. However, the ETc of summer maize decreased with distinct spatial variation. Spatially, winter wheat ETc increased significantly in the northeast NCP, covering the Beijing-Tianjin-Hebei areas. Meanwhile, significant increases in summer maize ETc were detected in the southwest NCP. The sensitivity and contribution analysis showed that ETc of winter wheat and summer maize was positively sensitive to temperature, wind speed, and sunshine hours while negatively to relative humidity. Moreover, wind speed and sunshine hours contributed most to changes in ETc (around 20%–40%).

Analysis of global trends of total column water vapour from multiple years of OMI observations

Abstract. In this study, we investigate trends in total column water vapour (TCWV) retrieved from measurements of the Ozone Monitoring Instrument (OMI) for the time range between January 2005 to December 2020. The trend analysis reveals, on global average, an annual increase in the TCWV amount of approximately +0.054 kg m−2 yr−1 or +0.21 % yr−1. After the application of a Z test (to the significance level of 5 %) and a false discovery rate (FDR) test to the results of the trend analysis, mainly positive trends remain, in particular over the northern subtropics in the eastern Pacific. Combining the relative TCWV trends with trends in air temperature, we also analyse trends in relative humidity (RH) on the local scale. This analysis reveals that the assumption of temporally invariant RH is not always fulfilled, as we obtain increasing and decreasing RH trends over large areas of the ocean and land surface and also observe that these trends are not limited to arid and humid regions, respectively. For instance, we find decreasing RH trends over the (humid) tropical Pacific Ocean in the region of the Intertropical Convergence Zone. Interestingly, these decreasing RH trends in the tropical Pacific Ocean coincide well with decreasing trends in precipitation. Moreover, by combining the trends of TCWV, surface temperature, and precipitation, we derive trends for the global water vapour turnover time (TUT) of approximately +0.02 d yr−1. Also, we obtain a TUT rate of change of around 8.4 % K−1, which is 2 to 3 times higher than the values obtained in previous studies.

Spatiotemporal Variations in Reference Evapotranspiration and Its Contributing Climatic Variables at Various Spatial Scales across China for 1984–2019

Reference evapotranspiration (ET0) is of great significance in studies of hydrological cycle, agricultural water resources, and hydrometeorology. The present study collected daily meteorological data at 536 meteorological stations in China from 1984 to 2019, calculated daily ET0 using the FAO Penman–Monteith equation, analyzed the spatial distribution and temporal variation characteristics of ET0 and meteorological variables at four different spatial scales (continental, regional, provincial, and local), and discussed the sensitivity of ET0 to the meteorological variables and the contribution rates of the meteorological variables to the ET0 variations. The results showed that ET0 increased at 406 out of the 536 stations (75.7%), with the trends being significant at 65 stations at the 5% significance level, and 147 at the 1% significance level. The slope calculated using Sen’s method and linear trend method showed that the annual ET0 at the continental scale increased by approximately 12 mm/decade. Most of the stations showed decreasing trends in relative humidity (Hm), sunshine duration (SD), and wind speed at 2 m height (U2) while increasing trends in the maximum air temperature (Tmax) and minimum air temperature (Tmin). ET0 was most sensitive to Hm (sensitivity coefficient, St = −0.66), followed by Tmax (St = 0.29), SD (St = 0.18), U2 (St = 0.16), and Tmin (St = 0.07). Most of the stations showed increasing trends in St for Hm (56.16%), Tmax (72.95%), Tmin (87.31%), and U2 (90.49%), and decreasing trends for SD (69.78%). The variations in Hm, Tmax, and Tmin increased the ET0 at most of the stations (82.28%, 98.13%, and 69.03%, respectively). The variations in SD and U2 decreased ET0 at most of the stations (66.04% and 56.34%, respectively). Some ET0 characteristics in a few regions can be well described using a single spatial scale. However, most regions exhibited significantly different ET0 characteristics across spatial scales. The results of this project can provide reference for hydrological analysis and agricultural water management under climate change conditions and provide data and information for other hydrology-related applications.