O'Fallon, MO Weather Forecast
Local 7-day forecast
Sunny
Track current conditions, temperature changes, wind, and the full daily outlook for O'Fallon, MO in one place.
Sunny, with a high near 90. South wind 3 to 7 mph.
Local Weather Overview
This forecast page for O'Fallon, MO is designed for quick trip planning, giving you a clean read on daytime highs, overnight lows, and changing conditions across the upcoming forecast window. Latest sync: Oct 8, 2026 12:09 PM CDT.
The active forecast window currently covers Oct 9 to Oct 14, 2026 for O'Fallon, MO.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Oct 9 to Oct 14, 2026
- Latest sync
- Oct 8, 2026 12:09 PM CDT
- Forecast office
- LSX
- Source
- NOAA / NWS
Daily Outlook
This Week in O'Fallon
Friday looks like the warmest upcoming period in O'Fallon at 90 degrees F.
Tuesday Night is the coolest period ahead with temperatures near 54 degrees F.
The strongest winds are forecast for Tuesday at about 10 mph NW.
Precipitation is mentioned in 5 upcoming forecast periods.
Forecast Details
- Last updated
- Oct 8, 2026 12:09 PM CDT
- Coverage
- 6 days
- Time zone
- America/Chicago
- Forecast office
- LSX
- Radar station
- KLSX
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
Clear, with a low around 61. South wind around 6 mph.
Mostly sunny. High near 85, with temperatures falling to around 81 in the afternoon. South wind 3 to 9 mph.
A chance of rain showers after 7pm. Mostly cloudy, with a low around 60. Chance of precipitation is 50%.
A chance of rain showers before 7am. Mostly sunny, with a high near 80. Chance of precipitation is 50%.
Mostly clear, with a low around 60.
Sunny, with a high near 90.
Mostly clear, with a low around 62.
A slight chance of rain showers after 7am. Sunny, with a high near 78. Chance of precipitation is 20%.
A slight chance of rain showers before 1am. Partly cloudy, with a low around 54. Chance of precipitation is 20%.
Sunny, with a high near 75.
A chance of rain showers after 7pm. Partly cloudy, with a low around 57. Chance of precipitation is 30%.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Friday
Oct 9
|
Sunny
|
90°F |
3 to 7 mph
S
|
|
Friday Night
Oct 9
|
Clear
|
61°F |
6 mph
S
|
|
Saturday
Oct 10
|
Mostly Sunny
|
85°F |
3 to 9 mph
S
|
|
Saturday Night
Oct 10
|
Chance Rain Showers
|
60°F |
7 mph
E
|
|
Sunday
Oct 11
|
Chance Rain Showers then Mostly Sunny
|
80°F |
5 mph
N
|
|
Sunday Night
Oct 11
|
Mostly Clear
|
60°F |
0 to 3 mph
S
|
|
Columbus Day
Oct 12
|
Sunny
|
90°F |
3 to 8 mph
SW
|
|
Monday Night
Oct 12
|
Mostly Clear
|
62°F |
5 to 9 mph
SW
|
|
Tuesday
Oct 13
|
Slight Chance Rain Showers
|
78°F |
10 mph
NW
|
|
Tuesday Night
Oct 13
|
Slight Chance Rain Showers
|
54°F |
6 mph
N
|
|
Wednesday
Oct 14
|
Sunny
|
75°F |
6 mph
E
|
|
Wednesday Night
Oct 14
|
Chance Rain Showers
|
57°F |
6 mph
SE
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around O'Fallon.
