The article presents the results of long-term observations of cosmic ray variations and changes in atmospheric parameters at midlatitudes in the Novosibirsk Region. The atmospheric response to Forbush decreases in galactic cosmic rays (CR) and solar proton events is analyzed. The analysis involves 181 Forbush decreases and 18 GLEs (Ground Level Enhancement) for the period 1967-2019. This makes it possible to examine the effect depending on season. The effect of increasing pressure during the Forbush decrease in cosmic rays is more pronounced in the autumn-winter period. Nonetheless, it also occurs in the warm season. For midlatitudes, there is also a tendency for pressure to increase after GLE. At the Forbush decrease front, with a decrease in CR intensity and an increase in atmospheric pressure, an increase in the average mass and surface temperature is observed. In the intensity recovery phase after the Forbush decrease, a decrease in the average mass and surface temperature occurs. The observed variations in atmospheric parameters are assumed to be due to changes in the ionization rate under the influence of cosmic rays in variations in atmospheric transparency and cloudiness.
