Chicago weather in October
In October, Chicago has an average high of 15 °C59 °F and an average low of 10 °C49 °F, with about 99 mm3.9 in of precipitation. It is the 5th warmest month of the year and ranks 4th for precipitation.
How October compares with other months
Compared with September, October is 6.8 °C12.2 °F cooler on average and wetter by 13 mm0.5 in. Compared with November, October is 6.3 °C11.4 °F warmer on average and wetter by 38 mm1.5 in. Daylight lasts about 11.0 hours around the middle of the month. Average relative humidity is 77% and the average cloud amount 58%.
Is October a good time to visit Chicago?
October is not among the most comfortable months by our comfort score: it is cool (average high 15 °C59 °F) and it is fairly wet (99 mm3.9 in). The most comfortable months in Chicago are June and July and September.
What to wear in October
For Chicago in October, pack long sleeves, a sweater and a medium jacket and an umbrella or light rain jacket.
October in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Chicago | 1559 | 1049 | 993.9 |
| Joliet | 1763 | 642 | 893.5 |
| Elgin | 1661 | 542 | 913.6 |
| Aurora | 1661 | 642 | 913.6 |
| South Bend | 1762 | 643 | 943.7 |
| Rockford | 1660 | 540 | 803.2 |
| Milwaukee | 1560 | 542 | 823.2 |
| Madison | 1559 | 439 | 803.2 |
| Grand Rapids | 1560 | 642 | 1094.3 |
Nearby places that are more than 1 °C1.8 °F cooler: Elgin, Aurora, Rockford and Milwaukee.
Other months in Chicago
- January0 °C32 °F / −5 °C23 °F
- February0 °C33 °F / −5 °C23 °F
- March5 °C41 °F / −1 °C31 °F
- April10 °C50 °F / 4 °C39 °F
- May15 °C59 °F / 9 °C47 °F
- June21 °C70 °F / 15 °C59 °F
- July25 °C77 °F / 20 °C68 °F
- August25 °C77 °F / 20 °C68 °F
- September22 °C71 °F / 16 °C62 °F
- October15 °C59 °F / 10 °C49 °F
- November9 °C47 °F / 3 °C38 °F
- December3 °C37 °F / −2 °C29 °F
Frequently asked questions
How warm is Chicago in October?
In October the average high in Chicago is 15 °C (59 °F) and the average low is 10 °C (49 °F).
Does it rain a lot in Chicago in October?
On average about 99 mm (3.9 in) of precipitation falls in October; it ranks 4th of the 12 months.
Is October the warmest month in Chicago?
No. The warmest month in Chicago is July, with an average high of 25 °C (77 °F). The coldest month is February, with an average low of -5 °C (23 °F).
How long is the day in Chicago in October?
In the middle of October the day in Chicago lasts about 11.0 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Chicago in October?
The average relative humidity in October is about 77%. This is a long-term average for the whole day.
How cloudy is Chicago in October?
On average about 58% of the sky is covered by cloud in October. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.