Illinois (Chicago)
October
Weather in Illinois for October 2025
Your guide to Illinois weather in October - trends and predictions
Until now, October 2025 in Illinois is slightly cooler than the historical average by -0.6 °F.
In general, the average temperature in Illinois at the beginning of October is 21.9 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 14 °F by the end of October.
Illinois in October brings notable rainfall, with an average of 16 rainy days and a total precipitation of 120.3 mm.
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Temperatures
Rain 🌧️
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15
Dry days
16
Rainy days
0
Snow days
17°/11°
Temperatures
23 km/h
Avg max wind
63 %
Avg humidity
Illinois Weather October
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What’s the Weather Like in Illinois This October?
Discover the average temperatures and weather trends across Illinois’s cities this October.
Temperatures trend during October in Illinois
See the weather trend as well as the moving average line
October weather in Illinois day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Oct. 1 |  Overcast | 22° /15° | 0 mm | 5 | |
| Oct. 2 |  Sunny | 22° /15° | 0.7 mm | 6 | |
| Oct. 3 |  Partly cloudy | 24° /15° | 3.7 mm | 6 | |
| Oct. 4 |  Moderate rain at times | 23° /16° | 2.7 mm | 6 | |
| Oct. 5 |  Cloudy | 24° /16° | 8.1 mm | 5 | |
| Oct. 6 |  Patchy rain possible | 22° /14° | 4.2 mm | 5 | |
| Oct. 7 | Moderate or heavy rain shower | 16° /11° | 4.4 mm | 4 | |
| Oct. 8 | Partly cloudy | 17° /11° | 0.4 mm | 5 | |
| Oct. 9 | Sunny | 19° /11° | 0.1 mm | 5 | |
| Oct. 10 | Sunny | 19° /12° | 0 mm | 5 | |
| Oct. 11 | Moderate or heavy rain shower | 21° /13° | 7.1 mm | 5 | |
| Oct. 12 | Moderate or heavy rain shower | 19° /13° | 6 mm | 4 | |
| Oct. 13 | Overcast | 17° /11° | 13.2 mm | 4 | |
| Oct. 14 | Moderate or heavy rain shower | 15° /11° | 9.4 mm | 3 | |
| Oct. 15 | Moderate or heavy rain shower | 14° /9° | 12.1 mm | 3 | |
| Oct. 16 | Overcast | 15° /8° | 0.1 mm | 4 | |
| Oct. 17 | Overcast | 16° /7° | 0.2 mm | 4 | |
| Oct. 18 | Sunny | 19° /8° | 0 mm | 5 | |
| Oct. 19 | Sunny | 17° /9° | 5.8 mm | 4 | |
| Oct. 20 | Sunny | 19° /9° | 0.2 mm | 5 | |
| Oct. 21 | Overcast | 18° /10° | 0.6 mm | 4 | |
| Oct. 22 | Overcast | 16° /9° | 0 mm | 4 | |
| Oct. 23 | Partly cloudy | 17° /9° | 0 mm | 4 | |
| Oct. 24 | Sunny | 17° /10° | 8.3 mm | 5 | |
| Oct. 25 |  Heavy rain at times | 16° /10° | 12.2 mm | 4 | |
| Oct. 26 | Overcast | 15° /11° | 1 mm | 4 | |
| Oct. 27 | Partly cloudy | 15° /9° | 1.2 mm | 4 | |
| Oct. 28 | Overcast | 13° /7° | 2.8 mm | 3 | |
| Oct. 29 | Overcast | 15° /9° | 4.3 mm | 4 | |
| Oct. 30 | Overcast | 14° /8° | 0.4 mm | 4 | |
| Oct. 31 | Partly cloudy | 10° /6° | 0 mm | 0.6 | |
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Important Notice
Our weather forecast for Illinois in October is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Illinois forecast closer to your planned date for the most up-to-date weather information.
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Illinois in October - FAQ
What are the expected maximum and minimum temperatures in Illinois during October?
Enjoy moderate daytime temperatures of up to 17° and cooler nights around 11°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Illinois during October?
Significant rainfall exceeding 120.3 mm is expected in Illinois during October, occurring over more than 16 days. Preparing for wet conditions is recommended in your planning.
Will it snow in Illinois in October 2025?
Illinois typically sees 0.0275 cm of snowfall during October.
What are the typical wind conditions in Illinois during October?
The average wind speed in Illinois during October is 23 km/h, suggesting breezy to windy conditions, depending on your activities.
October rainfall patterns in Illinois
Explore the daily rainfall trends and prepare for Illinoiss October weather 💧
UV exposure in Illinois during October
Stay informed about UV levels for safe outdoor activities throughout the month of October ☀️
Counties in Illinois
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Top locations in Illinois
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