Kankakee's winters are bitterly cold, with temperatures often dipping below freezing and averaging around -2°C in January, with frequent drops into the -18°C range. Spring arrives slowly, with March temperatures warming to a average of 6°C, but still fluctuating between -5°C and 21°C. Summer is mild, with June to August temperatures consistently hovering around 24-25°C, although occasional heatwaves can push them up to 35°C. Autumn brings a return to cooler temperatures, with October averaging around 14°C, before dropping back into the cold range in November. The coldest months are January and February, while July and August are the warmest, but only just.