Weather forecast for 10 daysO'Fallon, MO

Weather forecast for the weekend

Saturday Oct 17, 2026

  • 59°F
  • 37°F
Sunny
Sunny
  • Precip. probability: 0%
  • Precipitation: 0"
  • Wind: 2mphNE 45°
  • Humidity: 42%
  • UV index: 5
  • Sunrise: 7:14 am CDT
  • Sunset: 6:21 pm CDT
  • ▼
Today, sunny conditions are expected to continue.
The temperature will fluctuate from a high of a mild 59°F to a low of a wintry 37.4°F.
On today, conditions will be colder with a temperature more like November's typical high of 53.2°F.
Sunrise was at 7:14 am and sunset will be at 6:21 pm; the daylight will last for 11h and 7min.

Sunday Oct 18, 2026

  • 66°F
  • 37°F
Sunny
Sunny
  • Precip. probability: 5%
  • Precipitation: 0"
  • Wind: 7mphSSE 167°
  • Humidity: 51%
  • UV index: 5
  • Sunrise: 7:15 am CDT
  • Sunset: 6:20 pm CDT
  • ▼
Tomorrow, on Sunday, sunshine will likely continue with scattered clouds at most.
Temperature readings will span from a daytime high of an enjoyable 66.2°F to a night low of an icy 37.4°F.
This expected maximum temperature is expected to mirror October's typical high of 66.2°F.
Sunrise will be at 7:15 am and sunset at 6:20 pm; tomorrow's daylight will last for 11h and 5min.

10-day overview

Daily temperatures

Warmest period: Friday - Sunday 81°C.
Coldest day: today 59°C.

Chance of precipitation

Highest chance: Monday 26.10. 20%.

Long-term weather forecast

  • Saturday
  • Oct 17, 2026
  • 59°F
  • 37°F
Sunny
Sunny
  • Precip. probability: 0%
  • Precipitation: 0"
  • Wind: 2mphNE 45°
  • Humidity: 42%
  • UV index: 5
  • Sunrise: 7:14 am CDT
  • Sunset: 6:21 pm CDT
  • ▼
  • Sunday
  • Oct 18, 2026
  • 66°F
  • 37°F
Sunny
Sunny
  • Precip. probability: 5%
  • Precipitation: 0"
  • Wind: 7mphSSE 167°
  • Humidity: 51%
  • UV index: 5
  • Sunrise: 7:15 am CDT
  • Sunset: 6:20 pm CDT
  • ▼
  • Monday
  • Oct 19, 2026
  • 72°F
  • 41°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 6%
  • Precipitation: 0"
  • Wind: 4mphSSE 162°
  • Humidity: 54%
  • UV index: 5
  • Sunrise: 7:16 am CDT
  • Sunset: 6:18 pm CDT
  • ▼
  • Tuesday
  • Oct 20, 2026
  • 73°F
  • 43°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 9%
  • Precipitation: 0"
  • Wind: 4mphSE 145°
  • Humidity: 53%
  • UV index: 4
  • Sunrise: 7:17 am CDT
  • Sunset: 6:17 pm CDT
  • ▼
  • Wednesday
  • Oct 21, 2026
  • 77°F
  • 45°F
Mostly Sunny
Mostly Sunny
  • Precip. probability: 5%
  • Precipitation: 0"
  • Wind: 3mphS 188°
  • Humidity: 53%
  • UV index: 4
  • Sunrise: 7:18 am CDT
  • Sunset: 6:16 pm CDT
  • ▼
  • Thursday
  • Oct 22, 2026
  • 79°F
  • 45°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 5%
  • Precipitation: 0"
  • Wind: 4mphS 180°
  • Humidity: 52%
  • UV index: 4
  • Sunrise: 7:19 am CDT
  • Sunset: 6:14 pm CDT
  • ▼
  • Friday
  • Oct 23, 2026
  • 81°F
  • 46°F
Mostly Sunny
Mostly Sunny
  • Precip. probability: 5%
  • Precipitation: 0"
  • Wind: 6mphSE 135°
  • Humidity: 50%
  • UV index: 4
  • Sunrise: 7:20 am CDT
  • Sunset: 6:13 pm CDT
  • ▼
  • Saturday
  • Oct 24, 2026
  • 81°F
  • 48°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 4%
  • Precipitation: 0"
  • Wind: 6mphSSE 150°
  • Humidity: 51%
  • UV index: 4
  • Sunrise: 7:21 am CDT
  • Sunset: 6:12 pm CDT
  • ▼
  • Sunday
  • Oct 25, 2026
  • 81°F
  • 52°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 7%
  • Precipitation: 0"
  • Wind: 6mphSW 215°
  • Humidity: 54%
  • UV index: 4
  • Sunrise: 7:22 am CDT
  • Sunset: 6:11 pm CDT
  • ▼
  • Monday
  • Oct 26, 2026
  • 79°F
  • 52°F
Partly Cloudy
Partly Cloudy
  • Precip. probability: 20%
  • Precipitation: 0"
  • Wind: 5mphWSW 255°
  • Humidity: 58%
  • UV index: 4
  • Sunrise: 7:23 am CDT
  • Sunset: 6:09 pm CDT
  • ▼
Across the following ten days, a combination of dull and mostly clear weather is forecasted.
Rainfall is not predicted in O'Fallon in the upcoming period.
Temperature fluctuation will be noticeable in the upcoming period. Forecast highs will fluctuate between 59°F and 80.6°F, while the nightly low temperatures will show also a considerable swing, as the lowest temperatures will be recorded between 37.4°F and 51.8°F.
The warmest days will be Friday through next Sunday, with a maximum of 80.6°F; today is the coldest day, with a maximum temperature of 59°F.
Updated: Oct 17, 2026 @ 17:08:37 UTC
Published by: Weather U.S. | About Us
Data Sources | weather.com | Weather
Weather Forecasting & Climate

Frequently asked questions

Today, sunny and dry conditions are anticipated.

Today, the highest temperature in O'Fallon will be 59°F, while the lowest temperature will be 37.4°F.
Today, the highest temperature will be relatively lower than the average maximum temperature in October. The lowest temperature today will be noticeably lower than the average low of 48.7°F.

On Saturday, in O'Fallon, sunrise was at 7:14 am and sunset will be at 6:21 pm (CDT).

In O'Fallon, the length of the day today will be 11h and 7min.

On Sunday, clear and sunny conditions are expected.

Tomorrow, the highest temperature will be 66.2°F, while the lowest temperature will be 37.4°F.
Tomorrow, the maximum temperature will be in line with the average highest temperature in October. The lowest temperature tomorrow will be significantly lower than the average low of 48.7°F.

On Sunday, in O'Fallon, sunrise will be at 7:15 am and sunset at 6:20 pm (CDT).

In O'Fallon, the length of the day tomorrow will be 11h and 5min.