Kalisz's winters are cold and variable, with temperatures often dropping below freezing but occasionally rising into double digits. Spring brings a gradual warming trend, with March being the first month to experience above-average highs. Summer is warm and stable, with July typically the hottest month, while August and September see slight cooling. Autumn is mild, with October being the last month of the season to have average temperatures above freezing. Winters return in December, mirroring January's cold conditions.