In this study the aerosol influence on meteorological parameters (air temperature at 2 m, total cloud cover, specific humidity, precipitation) as well as spatio-temporal variations of SO2 and sulphates wet deposition on surfaces of water bodies are evaluated. The research was carried out for January and August of 2010 using results of online-integrated numerical weather prediction and atmospheric chemistry transport model Enviro-HIRLAM. The territories of interest are North-West Russia, countries of Northern Europe, Kola Peninsula and three large cities - Saint-Petersburg, Moscow (Russia) and Helsinki (Finland). Four model runs were performed: reference run (without aerosol effects included), run with direct, indirect and combined aerosol effects. Analysis of the modelled results demonstrates that aerosol effects were more significant during August 2010 than during January. In general, the direct effect led to decrease air temperature and total cloud cover, when the indirect and combined effects tend to increase these parameters. In addition, the direct effect decreased specific humidity in January and August. The indirect and combined effects increased this parameter in January and decreased in August. All three aerosol effects led to decrease in precipitation. It was found that the aerosol effects for the selected cities were more significant in August than in January. The considerable changes in meteorological parameters were found in Saint-Petersburg and Moscow during August and in Helsinki during January. The analysis of modeled SO2 concentration demonstrated the larger number of cases of transboundary pollution from the territory of the Kola Peninsula to the territory of the Northern Europe in August 2010 than in January (15 and 9 days respectively). According to the modelled results, SO2 was transported to the territories of water bodies (Barents, Norwegian and White Seas) more frequently in January than in August (20 vs 5 days respectively). In addition, SO2 concentrations over the Kola Peninsula and the territory of the Northern Europe countries were higher in January. The number of cases of wet deposition as well as amount of deposited sulphates were higher in August.