Weather forecast for tomorrowO'Fallon, IL
Weather forecast for tomorrow
Sunday Oct 18, 2026
- 66°F
- 39°F
Sunny
- Precip. probability: 4%
- Precipitation: 0"
- Wind: 7mphSSE 165°
- Humidity: 54%
- UV index: 5
- Sunrise: 7:12 am CDT
- Sunset: 6:17 pm CDT
- details ▼
Tomorrow, on Sunday, clear and sunny conditions are also expected.
A significant variation in temperature is predicted, ranging from a high of a comfortable 66.2°F to a low of a wintry 39.2°F.
Tomorrow's forecasted high will be in line with October's typical peak of 66.6°F.
Sunrise will be at 7:12 am and sunset at 6:17 pm; tomorrow's daylight will last for 11h and 5min.
A significant variation in temperature is predicted, ranging from a high of a comfortable 66.2°F to a low of a wintry 39.2°F.
Tomorrow's forecasted high will be in line with October's typical peak of 66.6°F.
Sunrise will be at 7:12 am and sunset at 6:17 pm; tomorrow's daylight will last for 11h and 5min.
Hourly overview
Hourly temperatures
Warmest hour: 3 pm 66°C.
Coldest hour: 6 am 39°C.
Coldest hour: 6 am 39°C.
Chance of precipitation
Highest chance: 3 am - 6 am 4%.
Hourly weather forecast
- 12 am
- 43°F
- Feels like:43°F
Clear
- Precip. probability: 1%
- Precipitation: 0"
- Wind: 1mphSE 131°
- Humidity: 88%
- Pressure: 30.47"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
- 2 am
- 41°F
- Feels like:41°F
Clear
- Precip. probability: 2%
- Precipitation: 0"
- Wind: 2mphSE 141°
- Humidity: 87%
- Pressure: 30.47"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
- 4 am
- 39°F
- Feels like:39°F
Clear
- Precip. probability: 4%
- Precipitation: 0"
- Wind: 2mphSSE 156°
- Humidity: 90%
- Pressure: 30.47"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
- 6 am
- 39°F
- Feels like:39°F
Clear
- Precip. probability: 4%
- Precipitation: 0"
- Wind: 1mphSSE 155°
- Humidity: 91%
- Pressure: 30.47"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
Sunrise: 7:12 am
- 8 am
- 41°F
- Feels like:41°F
Sunny
- Precip. probability: 3%
- Precipitation: 0"
- Wind: 2mphSSE 153°
- Humidity: 87%
- Pressure: 30.5"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
- 10 am
- 52°F
- Feels like:50°F
Sunny
- Precip. probability: 0%
- Precipitation: 0"
- Wind: 6mphSSE 165°
- Humidity: 62%
- Pressure: 30.5"Hg
- Visibility: 10mi
- UV index: 2
- details ▼
- 12 pm
- 59°F
- Feels like:59°F
Sunny
- Precip. probability: 0%
- Precipitation: 0"
- Wind: 7mphS 179°
- Humidity: 46%
- Pressure: 30.45"Hg
- Visibility: 10mi
- UV index: 4
- details ▼
- 2 pm
- 64°F
- Feels like:64°F
Sunny
- Precip. probability: 0%
- Precipitation: 0"
- Wind: 7mphS 172°
- Humidity: 38%
- Pressure: 30.39"Hg
- Visibility: 10mi
- UV index: 4
- details ▼
- 4 pm
- 64°F
- Feels like:64°F
Sunny
- Precip. probability: 0%
- Precipitation: 0"
- Wind: 7mphSSE 168°
- Humidity: 34%
- Pressure: 30.36"Hg
- Visibility: 10mi
- UV index: 1
- details ▼
- 6 pm
- 61°F
- Feels like:61°F
Sunny
- Precip. probability: 0%
- Precipitation: 0"
- Wind: 5mphSSE 151°
- Humidity: 45%
- Pressure: 30.36"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
Sunset: 6:17 pm
- 8 pm
- 52°F
- Feels like:52°F
Clear
- Precip. probability: 1%
- Precipitation: 0"
- Wind: 3mphSE 137°
- Humidity: 68%
- Pressure: 30.36"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
- 10 pm
- 48°F
- Feels like:48°F
Clear
- Precip. probability: 1%
- Precipitation: 0"
- Wind: 2mphSE 145°
- Humidity: 82%
- Pressure: 30.36"Hg
- Visibility: 10mi
- UV index: 0
- details ▼
Tomorrow, on Sunday, primarily bright and sunny weather is anticipated.
The temperature will vary between a minimum of 37.4°F and a maximum of 66.2°F. The warmest part of the day is anticipated around 3 pm.
The maximum temperature will be in line with the average high of 66.6°F in October. Tomorrow, the overnight low is more close to November's usual minimum of 38.1°F than October's 48.7°F.
The temperature will vary between a minimum of 37.4°F and a maximum of 66.2°F. The warmest part of the day is anticipated around 3 pm.
The maximum temperature will be in line with the average high of 66.6°F in October. Tomorrow, the overnight low is more close to November's usual minimum of 38.1°F than October's 48.7°F.
Updated: Oct 18, 2026 @ 00:37:08 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
Tomorrow, skies will stay clear and sunny.
Tomorrow, the highest temperature will be 66.2°F, while the lowest temperature will be 39.2°F.
Tomorrow, the highest temperature will be in line with the average maximum temperature in October. The lowest temperature will be uncommonly lower than the average low of 48.7°F.
Tomorrow, the highest temperature will be in line with the average maximum temperature in October. The lowest temperature will be uncommonly 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).
In O'Fallon, the length of the day tomorrow will be 11h and 5min.
