Weather forecast for 10 daysO'Fallon, IL
Weather forecast for the weekend
Sunday Oct 18, 2026
- 66°F
- 39°F
Sunny
- Precip. probability: 4%
- Precipitation: 0"
- Wind: 8mphSSE 165°
- Humidity: 54%
- UV index: 5
- Sunrise: 7:12 am CDT
- Sunset: 6:17 pm CDT
- details ▼
Today, clear and sunny conditions are expected.
A daytime temperature reaching up to a breezy 66.2°F will sharply contrast with a nighttime low of a cold 39.2°F.
Today's high temperature will mirror the usual October maximum of 66.6°F.
Sunrise will be at 7:12 am and sunset at 6:17 pm; the daylight will last for 11h and 5min.
A daytime temperature reaching up to a breezy 66.2°F will sharply contrast with a nighttime low of a cold 39.2°F.
Today's high temperature will mirror the usual October maximum of 66.6°F.
Sunrise will be at 7:12 am and sunset at 6:17 pm; the daylight will last for 11h and 5min.
10-day overview
Daily temperatures
Warmest day: Sunday 25.10. 82°C.
Coldest day: today 66°C.
Coldest day: today 66°C.
Chance of precipitation
Highest chance: Tuesday 27.10. 8%.
Long-term weather forecast
- Sunday
- Oct 18, 2026
- 66°F
- 39°F
Sunny
- Precip. probability: 4%
- Precipitation: 0"
- Wind: 8mphSSE 165°
- Humidity: 54%
- UV index: 5
- Sunrise: 7:12 am CDT
- Sunset: 6:17 pm CDT
- details ▼
- Monday
- Oct 19, 2026
- 72°F
- 41°F
Mostly Sunny
- Precip. probability: 5%
- Precipitation: 0"
- Wind: 4mphS 171°
- Humidity: 54%
- UV index: 5
- Sunrise: 7:13 am CDT
- Sunset: 6:16 pm CDT
- details ▼
- Tuesday
- Oct 20, 2026
- 73°F
- 43°F
Partly Cloudy
- Precip. probability: 5%
- Precipitation: 0"
- Wind: 4mphE 91°
- Humidity: 52%
- UV index: 4
- Sunrise: 7:14 am CDT
- Sunset: 6:14 pm CDT
- details ▼
- Wednesday
- Oct 21, 2026
- 77°F
- 45°F
Sunny
- Precip. probability: 5%
- Precipitation: 0"
- Wind: 2mphSW 234°
- Humidity: 50%
- UV index: 4
- Sunrise: 7:15 am CDT
- Sunset: 6:13 pm CDT
- details ▼
- Thursday
- Oct 22, 2026
- 77°F
- 45°F
Sunny
- Precip. probability: 5%
- Precipitation: 0"
- Wind: 4mphW 280°
- Humidity: 53%
- UV index: 4
- Sunrise: 7:16 am CDT
- Sunset: 6:12 pm CDT
- details ▼
- Friday
- Oct 23, 2026
- 79°F
- 46°F
Mostly Sunny
- Precip. probability: 5%
- Precipitation: 0"
- Wind: 6mphESE 122°
- Humidity: 52%
- UV index: 4
- Sunrise: 7:17 am CDT
- Sunset: 6:10 pm CDT
- details ▼
- Saturday
- Oct 24, 2026
- 81°F
- 48°F
Partly Cloudy
- Precip. probability: 5%
- Precipitation: 0"
- Wind: 6mphSSE 153°
- Humidity: 49%
- UV index: 4
- Sunrise: 7:18 am CDT
- Sunset: 6:09 pm CDT
- details ▼
- Sunday
- Oct 25, 2026
- 82°F
- 50°F
Partly Cloudy
- Precip. probability: 4%
- Precipitation: 0"
- Wind: 6mphSSW 213°
- Humidity: 48%
- UV index: 4
- Sunrise: 7:19 am CDT
- Sunset: 6:08 pm CDT
- details ▼
- Monday
- Oct 26, 2026
- 79°F
- 48°F
Partly Cloudy
- Precip. probability: 5%
- Precipitation: 0"
- Wind: 6mphSW 227°
- Humidity: 50%
- UV index: 4
- Sunrise: 7:20 am CDT
- Sunset: 6:06 pm CDT
- details ▼
- Tuesday
- Oct 27, 2026
- 77°F
- 52°F
Mostly Cloudy
- Precip. probability: 8%
- Precipitation: 0"
- Wind: 6mphS 183°
- Humidity: 51%
- UV index: 3
- Sunrise: 7:21 am CDT
- Sunset: 6:05 pm CDT
- details ▼
Over the next ten days, a combination of clear and cloudy weather is anticipated.
Rainfall is not expected in O'Fallon in the upcoming period.
Temperature differences will be noticeable across the forecast period. The maximum temperature will vary between 66.2°F and 82.4°F, while there will be also a marked difference in overnight low temperatures, as the overnight lows will vary from 39.2°F to 51.8°F.
Next Sunday is expected to be the warmest, reaching up to 82.4°F; today is the coldest day, with a maximum temperature of 66.2°F.
Rainfall is not expected in O'Fallon in the upcoming period.
Temperature differences will be noticeable across the forecast period. The maximum temperature will vary between 66.2°F and 82.4°F, while there will be also a marked difference in overnight low temperatures, as the overnight lows will vary from 39.2°F to 51.8°F.
Next Sunday is expected to be the warmest, reaching up to 82.4°F; today is the coldest day, with a maximum temperature of 66.2°F.
Updated: Oct 18, 2026 @ 05:03:26 UTC
Published by: Weather U.S. | About Us
Data Sources | weather.com | Weather
Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | weather.com | Weather
Weather Forecasting & Climate
Frequently asked questions
On Sunday, the forecast calls for abundant sunshine.
Today, the maximum temperature will be 66.2°F, while the minimum temperature will be 39.2°F.
Today, the highest temperature will be in line with the average maximum temperature in October. The lowest temperature today will be significantly lower than the average low of 48.7°F.
Today, the highest temperature will be in line with the average maximum temperature in October. The lowest temperature today will be significantly lower than the average low of 48.7°F.
On Sunday, in O'Fallon, sunrise will be at 7:12 am and sunset at 6:17 pm (CDT).
Today, the daylight will last for 11h and 5min.
