Seasonal Variation in Microclimates and the Role of Regional Weather and Environmental Factors

Abstract

Microclimates are an important component of our ecosystem, and can impact human health through heat-related injuries or by affecting disease vectors. Research on microclimates can be difficult; our understanding of the temporal and environmental variation of microclimates is limited. Microclimate data (temperature and relative humidity) were collected over a twelve-month period in a small community in Ecuador, and summarized for over each 24-hour collection period. Using generalized linear models with generalized estimating equations, we assessed the variability of microclimate variables across time and environmental variables, including urbanicity, elevation and vegetation coverage. With local weather station and remotely-sensed climate data, we assessed the relationship between regional weather and microclimates. Two-hundred and eighty-seven log-days of data were collected; the absolute maximum temperature was in July, and the absolute minimum occurred in August. Relative humidity of 100% occurred frequently during the sampling period; the absolute minimum occurred in March. Some microclimate variables were more temporally stable than others (mean, median, and minimum temperature and maximum relative humidity); urban sites had higher temperature variability (p=0.0169) and rural sites had higher mean relative humidity (p=0.0137), compared to suburban areas. Microclimate temperature variables were associated with remotely-sensed surface temperature (p=0.047). Miicroclimate minimum (p=0.0001) and mean (p=0.045) temperature were associated with climate station temperature minimum and mean measures, respectively. Relative humidity mean (p<0.0001), median (p<0.0001), minimum (p=0.038), and maximum (p=0.0018) were associated with the number of days with precipitation at the climate station. These data demonstrate the need for climate and health researchers to reconsider the meaning and impact of climate variables across spatial scales.