WeatherArchive / Climate averages / Chicago
Chicago climate: average weather by month
Chicago averages 50°F (10°C) over the year. July is warmest, with highs around 80°F (27°C); January is coldest, with lows near 19°F (-7°C). About 39 inches (982 mm) of precipitation falls on roughly 121 days a year, from 30 years of ERA5 data (1996–2025).
| Month | Avg high | Avg low | Precip. | Days ≥1 mm | Sunshine / day |
|---|---|---|---|---|---|
| January | -0.9°C | -7.2°C | 59.0 mm | 9.1 | 5.5 h |
| February | 0.6°C | -6.6°C | 56.2 mm | 7.8 | 7.0 h |
| March | 5.4°C | -1.5°C | 70.7 mm | 9.9 | 8.5 h |
| April | 11.4°C | 4.3°C | 97.8 mm | 12.0 | 9.3 h |
| May | 17.9°C | 10.8°C | 111.1 mm | 12.1 | 10.5 h |
| June | 24.2°C | 17.3°C | 99.9 mm | 11.9 | 11.9 h |
| July | 26.6°C | 20.2°C | 100.7 mm | 11.2 | 12.3 h |
| August | 25.8°C | 19.8°C | 96.3 mm | 11.0 | 11.6 h |
| September | 22.5°C | 16.2°C | 77.9 mm | 8.7 | 10.0 h |
| October | 15.6°C | 9.5°C | 90.4 mm | 10.0 | 7.9 h |
| November | 8.3°C | 2.6°C | 60.0 mm | 8.3 | 6.1 h |
| December | 2.2°C | -3.3°C | 62.3 mm | 9.4 | 5.1 h |
Record high 1996–2025: 37.4°C on 2022-06-21. Record low: -32.5°C on 2019-01-31.
Source: Open-Meteo Historical Weather API (CC BY 4.0). Values are ERA5 reanalysis model data on a ~9–25 km grid, not readings from a weather station, so a single town’s thermometer can differ by a few degrees and local showers can be missed. Grid cell 41.86, -87.65 at 241 m. For snowfall, humidity and a best-time-to-visit score, open Chicago in the climate tool.