O’Fallon, Missouri

Last updated: 2:57 PM CDT  ·  Refresh
26°C
Feels like 27°
Mostly Clear
▲ 27°  /  ▼ 16°
Wind
3 mph ENE
Humidity
50%
Dew Point
15°
Pressure
29.59 inHg
Visibility
9 mi
UV Index
9.1
Cloud Cover
11%
Sunrise
5:38 AM
Sunset
8:31 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: O’Fallon is currently mostly clear at 26°C. Dry conditions are expected through the next 24 hours. Sunrise: 5:38AM · Sunset: 8:31PM.

Alerts

No active alerts for this location.
44 AQI · Good Dominant: O3 Air Quality
Hourly Forecast · Next 24 Hours
Now
26°
3%
3 PM
27°
3%
4 PM
27°
3%
5 PM
27°
3%
6 PM
27°
3%
7 PM
25°
3%
8 PM
24°
5%
9 PM
22°
5%
10 PM
21°
5%
11 PM
21°
5%
12 AM
20°
5%
1 AM
19°
12%
2 AM
19°
21%
3 AM
19°
21%
4 AM
19°
20%
5 AM
17°
20%
6 AM
17°
9%
7 AM
18°
16%
8 AM
19°
16%
9 AM
21°
17%
10 AM
22°
28%
11 AM
22°
28%
12 PM
23°
33%
1 PM
26°
37%
7-Day Forecast
Today
27° 16°
Partly Cloudy.
Wed
29° 17°
Mostly Cloudy with a 42% chance of rain.
Thu
32° 20°
Rain, 90% chance.
Fri
31° 21°
Heavy Rain, 90% chance.
Sat
35° 22°
Drizzle, 62% chance.
Sun
37° 23°
Clear with a 47% chance of rain.
Mon
38° 23°
Clear with a 24% chance of rain.
TimeTempConditionsPrecipWindHumidity
Now 26° Mostly Clear 3% 3 mph ENE 50%
3 PM 27° Partly Cloudy 3% 4 mph NE 50%
4 PM 27° Mostly Cloudy 3% 3 mph ENE 53%
5 PM 27° Partly Cloudy 3% 4 mph E 56%
6 PM 27° Mostly Cloudy 3% 4 mph E 62%
7 PM 25° Mostly Cloudy 3% 4 mph E 66%
8 PM 24° Overcast 5% 4 mph E 68%
9 PM 22° Overcast 5% 5 mph E 71%
10 PM 21° Overcast 5% 4 mph ESE 73%
11 PM 21° Overcast 5% 4 mph SE 75%
12 AM 20° Overcast 5% 4 mph SE 76%
1 AM 19° Mostly Cloudy 12% 5 mph SSE 75%
2 AM 19° Overcast 21% 5 mph SSE 75%
3 AM 19° Overcast 21% 5 mph SSE 75%
4 AM 19° Mostly Cloudy 20% 5 mph SSE 75%
5 AM 17° Overcast 20% 5 mph SSE 76%
6 AM 17° Overcast 9% 6 mph SSE 76%
7 AM 18° Overcast 16% 6 mph S 72%
8 AM 19° Overcast 16% 6 mph S 72%
9 AM 21° Overcast 17% 7 mph SSW 70%
10 AM 22° Drizzle 28% 7 mph SSW 70%
11 AM 22° Drizzle 28% 7 mph SSW 69%
12 PM 23° Drizzle 33% 7 mph SSW 68%
1 PM 26° Drizzle 37% 7 mph SSW 66%
15-Day Forecast
Today
6/23
Partly Cloudy
5%
16°
27°
Wed
6/24
Mostly Cloudy
42%
17°
29°
Thu
6/25
Rain
90%
20°
32°
Fri
6/26
Heavy Rain
90%
21°
31°
Sat
6/27
Drizzle
62%
22°
35°
Sun
6/28
Clear
47%
23°
37°
Mon
6/29
Clear
24%
23°
38°
Tue
6/30
Thunderstorm
52%
24°
38°
Wed
7/1
Drizzle
66%
24°
38°
Thu
7/2
Drizzle
63%
23°
36°
Fri
7/3
Drizzle
63%
24°
32°
Sat
7/4
Drizzle
66%
22°
34°
Sun
7/5
Drizzle
66%
21°
33°
Mon
7/6
Drizzle
66%
21°
32°
Tue
7/7
Drizzle
66%
21°
33°
44
Good
U.S. Air Quality Index · Dominant: O3
50 100 150 200

Air quality is satisfactory and poses little or no health risk.

Pollutant Breakdown · Today
PM2.5
Fine particulate matter
26 AQI 4.6 µg/m³
O3
Ground-level ozone
Dominant
44 AQI 48 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Wed 44 Good 44 26
Thu 41 Good 41 40
Fri 58 Moderate 58 34
About the Air Quality Index
0–50 Good
51–100 Moderate
101–150 Unhealthy for Sensitive Groups
151–200 Unhealthy
201–300 Very Unhealthy
301–500 Hazardous

The U.S. AQI runs 0–500. The overall value equals the highest individual pollutant sub-index, and the dominant pollutant is the one driving it. PM2.5 (fine particles) is reported in µg/m³ and ozone (O3) in ppb. Forecast source: NWS NAQFC.

1000850700500400300250200150100 -40-30-20-10010203040 0.41247101624 LCLLFCEL0°C Temperature (°C) Pressure (hPa)
Temp Dewpoint Parcel (SB) CAPE CIN Dry adiabat Moist adiabat Mixing ratio
RAP
Valid Tue Jun 23, 18:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 50 60 70 80 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE54 J/kg
MLCAPE7 J/kg
MUCAPE54 J/kg
SBCIN0 J/kg
MLCIN0 J/kg
Lifted Index2.2
Kinematics
0–6 km Shear30 kt
0–1 km Shear3 kt
Eff. Shear—
0–1 km SRH12
0–3 km SRH-91
Eff. SRH—
Storm Motion256° @ 18 kt
0–1 km EHI0.0
Composite Parameters
Sig. Tornado0.0
STP (eff)—
Supercell—
K-Index17.4
Thermo & Levels
PWAT1.02 in
0–3 km LR6.6 °C/km
700–500 LR5.8 °C/km
Total Totals36.8
LCL846 hPa
LFC1002 hPa
EL782 hPa
Freezing Lvl13,451 ft