O'Fallon, Missouri Weather Forecast
Today in O'Fallon: clear skies with a high near 75°F and a low around 49°F. Rain chance 1%. No day tops a 20% rain chance through Thursday. Highs run 73 to 77°F through Thursday.
Forecast updated 3:05 AM CDT, Oct 23
Active Weather Alerts
7-Day Forecast for O'Fallon
Today 10/23
75°49°
Sat 10/24
75°49°
Sun 10/25
77°49°
Mon 10/26
76°51°
Tue 10/27
73°51°
Wed 10/28
74°50°
Thu 10/29
10%
73°52°
Next 24 Hours
| Now | 9 AM | 10 AM | 11 AM | 12 PM | 1 PM | 2 PM | 3 PM | 4 PM | 5 PM | 6 PM | 7 PM | 8 PM | 9 PM | 10 PM | 11 PM | Sat12 AM | 1 AM | 2 AM | 3 AM | 4 AM | 5 AM | 6 AM | 7 AM | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sky | | | | | | | | | | | | |  | | | | |  | | | | | | |
| Temp | 50° | 56° | 62° | 67° | 71° | 74° | 75° | 75° | 75° | 74° | 69° | 65° | 62° | 60° | 59° | 57° | 57° | 56° | 54° | 53° | 52° | 51° | 50° | 49° |
| Rain | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 0% | 1% | 1% | 1% | 1% | 1% | 1% | 1% | 1% | 1% | 1% | 1% | 1% | 1% | 1% | 1% |
| Wind | SE 2 | SE 3 | SSE 3 | SSE 3 | SSE 4 | SSE 5 | SE 5 | SE 5 | SE 5 | SE 4 | ESE 3 | ESE 3 | SE 3 | SE 3 | SE 3 | SE 4 | SE 4 | SSE 4 | SSE 3 | SSE 3 | SSE 3 | SSE 3 | SE 2 | SE 2 |
Growing Conditions
Growing degree days
4,371
since Apr 1, base 50°F
Rain, last 30 days
0.82 in
model analysis
Rain, year to date
41.78 in
since Jan 1
2-inch soil temperature
57°F
yesterday, daily average
Reference ET, last 7 days
0.69 in
FAO-56 grass reference
Through Oct 22. Season totals use model analysis for this point and update every morning.
Soil, ET and spray tools for O'Fallon →
Current Stats & Observations
NWS Forecast
About O'Fallon Weather
O'Fallon sits at about 610 feet above sea level in St. Charles County, Missouri. About 88,673 people live in the O'Fallon area. Official forecasts and warnings for the area come from the National Weather Service LSX office, and the nearest NEXRAD radar site is KLSX. The city is in USDA plant hardiness zone 6b, where the coldest winter night typically falls between -5 to 0°F. Over the past ten years the last spring freeze has come around Apr 15 and the first fall freeze around Nov 3.
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