Tilastoja Suomen ilmastosta ja merestä 1991–2020

Abstract

This report consists of climate statistics for air pressure, temperature, relative humidity, precipitation, snow depth, wind, sunshine and global radiation for the normal period covering the years 1991–2020. In addition for the first time oceanographic statistics for sea water level, sea water temperature and sea ice are included. Based on the station and gridded data the new 1991–2020 normal period is approximately 0.6 °C warmer in Finland compared to the previous 1981–2010 period. The new normal period is approximately 1.3 °C warmer when compared to the 1961–1990 period. Climate and oceanographic statistics can be used for example when anomalies for current conditions need to be calculated and put in a historical context. In addition they help in decision-making when it is needed to approximate conditions months into the future. And lastly normal periods provide a way to monitor the progression of climate change. The calculation of the normal period statistics have been carried out following the World Meteorological Organization (WMO) guidelines. Like with previous normal periods, some stricter guidelines were followed nationally, for example in the way missing observations were handled. The period 1991–2020 is both nationally and internationally the official normal period before the next one covering 2001–2030 is taken into use.