Chicago Climate by Month – Rainy Season, Temperature Averages
Summary
The climate figures for Chicago are averaged from 2016–2025 observations (10 years). Annual rainfall averages about 1,145 mm.
The rainy season runs May–October. The wettest month is July with 149.7 mm across 13 rain days; the driest is February at just 58.6 mm.
The hottest month is July (average high 27.1°C) and the coolest is January (0.1°C).
The most comfortable time to visit Chicago is February — less rain and milder heat.
Monthly averages · 2016–2025
| Monthly averages | High | Low | Rainfall | Rainy season |
|---|---|---|---|---|
| January | 0.1° | -6.7° | 66 mm | 10 |
| February | 2.6° | -5.8° | 59 mm | 9 |
| March | 7.8° | -0.2° | 94 mm | 12 |
| April | 12.7° | 4.1° | 99 mm | 14 |
| May | 18.7° | 10.1° | 125 mm | 12 |
| June | 25.5° | 16.6° | 111 mm | 11 |
| July | 27.1° | 19.5° | 150 mm | 13 |
| August | 26.6° | 19.1° | 105 mm | 12 |
| September | 23.8° | 16.3° | 92 mm | 10 |
| October | 16.8° | 9.3° | 124 mm | 12 |
| November | 8.8° | 1.8° | 60 mm | 8 |
| December | 3.3° | -3.4° | 60 mm | 9 |