Chicago, Illinois weather in May

Averages from 2021–2025 (155 days of record).

Average high: 67°F
Average low: 51°F
Rainy days: ~11 per month
Total precipitation: 3.6 in
Warmest recorded: 90°F
Coldest recorded: 36°F

Expect May days in Chicago, Illinois to top out around 67°F and cool to about 51°F overnight, with roughly 11 days of measurable rain across the month. In recent years May has ranged from 36°F to 90°F.

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Current Chicago, Illinois forecast → · Historical data by Open-Meteo (ERA5).