Chicago climate
Chicago is warmest in July, with average highs of 28 °C, and coldest in January, when nights average -7.0 °C. May is the wettest month (116 mm) and February the driest (53 mm). Figures are 1991–2020 climate normals.
Across a full year Chicago averages 1,009 mm of rain, 81 days above 25 °C and 104 days below freezing.
United States · 179 m elevation · population 2,664,452 · 1991–2020 normals
Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month
- Warmest month July 28 °C
- Coldest month January -7.0 °C
- Driest month February 53 mm
- Wettest month May 116 mm
- Least cloud September 48 % cloud
- Hottest on record July 37 °C
- Coldest on record January -32 °C
What to expectChicago through the year
Chicago has a clear annual cycle: average daily highs run from -0.2 °C in January to 28 °C in July, a swing of 28 °C in mean temperature across the year.
Counted across a normal year, 81 days a year reach 25 °C, 19 of them reach 30 °C, 104 nights drop below freezing. The warmest reading in the 1991–2020 record is 37 °C, in July.
Rain is strongly seasonal. May averages 116 mm against 53 mm in February — 2.2 times as much. Planning around the dry months matters more here than planning around temperature.
Month by month
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | -0.2 °C | 62 mm | 70 % |
| February | 1.5 °C | 53 mm | 66 % |
| March | 6.6 °C | 70 mm | 64 % |
| April | 13.0 °C | 108 mm | 63 % |
| May | 19.5 °C | 116 mm | 61 % |
| June | 25.3 °C | 105 mm | 57 % |
| July | 27.9 °C | 99 mm | 50 % |
| August | 26.9 °C | 98 mm | 50 % |
| September | 23.2 °C | 79 mm | 48 % |
| October | 16.4 °C | 86 mm | 56 % |
| November | 8.8 °C | 72 mm | 63 % |
| December | 2.6 °C | 61 mm | 70 % |
Temperature month by month
| Month | Avg high | Avg low | Mean | Record high | Record low | Days above 25 °C | Days above 30 °C | Days below 0 °C |
|---|---|---|---|---|---|---|---|---|
| January | -0.2 °C | -7.0 °C | -4.0 °C | 16.1 °C | -32.5 °C | 0 | 0 | 27 |
| February | 1.5 °C | -6.0 °C | -2.8 °C | 18.6 °C | -28.6 °C | 0 | 0 | 24 |
| March | 6.6 °C | -1.2 °C | 2.1 °C | 24.8 °C | -21.1 °C | 0 | 0 | 19 |
| April | 13.0 °C | 4.7 °C | 8.2 °C | 26.3 °C | -7.2 °C | 0 | 0 | 4 |
| May | 19.5 °C | 11.3 °C | 14.9 °C | 33.4 °C | -1.3 °C | 6 | 0 | 0 |
| June | 25.3 °C | 17.5 °C | 21.0 °C | 36.5 °C | 6.4 °C | 16 | 4 | 0 |
| July | 27.9 °C | 20.4 °C | 23.8 °C | 37.4 °C | 12.6 °C | 24 | 8 | 0 |
| August | 26.9 °C | 19.9 °C | 23.1 °C | 35.4 °C | 11.4 °C | 22 | 5 | 0 |
| September | 23.2 °C | 16.1 °C | 19.3 °C | 34.3 °C | 3.8 °C | 11 | 2 | 0 |
| October | 16.4 °C | 9.5 °C | 12.5 °C | 29.7 °C | -1.1 °C | 1 | 0 | 0 |
| November | 8.8 °C | 2.7 °C | 5.3 °C | 23.4 °C | -15.0 °C | 0 | 0 | 9 |
| December | 2.6 °C | -3.1 °C | -0.6 °C | 18.6 °C | -22.0 °C | 0 | 0 | 22 |
Rain, sun and wind month by month
| Month | Rainfall | Wet days | Daylight | Cloud cover | Humidity | Wind |
|---|---|---|---|---|---|---|
| January | 62 mm | 9 | 9.5 h/day | 70 % | 75 % | 24 km/h |
| February | 53 mm | 7 | 11 h/day | 66 % | 74 % | 23 km/h |
| March | 70 mm | 10 | 12 h/day | 64 % | 74 % | 23 km/h |
| April | 108 mm | 12 | 13 h/day | 63 % | 72 % | 25 km/h |
| May | 116 mm | 12 | 15 h/day | 61 % | 73 % | 23 km/h |
| June | 105 mm | 12 | 15 h/day | 57 % | 72 % | 20 km/h |
| July | 99 mm | 11 | 15 h/day | 50 % | 70 % | 19 km/h |
| August | 98 mm | 11 | 14 h/day | 50 % | 72 % | 18 km/h |
| September | 79 mm | 9 | 13 h/day | 48 % | 70 % | 20 km/h |
| October | 86 mm | 9 | 11 h/day | 56 % | 70 % | 23 km/h |
| November | 72 mm | 9 | 9.8 h/day | 63 % | 71 % | 24 km/h |
| December | 61 mm | 9 | 9.2 h/day | 70 % | 74 % | 24 km/h |
Where Chicago ranks
| Ranking | Position | Value |
|---|---|---|
| The coolest places in North America in April | 30thof 50 | 13 °C |
| The coolest places in North America in January | 30thof 50 | -0.2 °C |
| The coolest places in North America in March | 30thof 50 | 6.6 °C |
| The coolest places in North America in December | 31stof 50 | 2.6 °C |
| The coolest places in North America in February | 32ndof 50 | 1.5 °C |
| The coolest places in North America in November | 37thof 50 | 8.8 °C |
Planning a trip? See the best time to visit Chicago.
QuestionsCommon questions about Chicago’s climate
When is the best time to visit Chicago?
That depends on what you want, so the honest answer is a comparison rather than a single month. June, August, September sit closest to 20 °C on average, July is the warmest month and February the driest. The month-by-month table above has the full picture.
How hot does Chicago get?
In July, the warmest month, daily highs average 28 °C. About 19 days a year pass 30 °C. The highest value in the 1991–2020 record is 37 °C.
How cold does it get in winter?
Nights average -7.0 °C in January, the coldest month. A normal year has 104 nights below freezing.
Which month is wettest in Chicago?
May, averaging 116 mm over 12 days with rain. The driest month is February with 53 mm. The year as a whole averages 1,009 mm.
Are these figures a forecast?
No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Chicago rather than what any particular week will bring. Individual years can differ substantially from the normal.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.