O’Fallon, Missouri

Last updated: 1:40 PM CDT  ·  Refresh
79°
Feels like 80°
Clear
▲ 82°  /  ▼ 61°
Wind
3 mph E
Humidity
49%
Dew Point
58°
Pressure
29.60 inHg
Visibility
9 mi
UV Index
9.7
Cloud Cover
3%
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 clear at 79°F. 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
79°
3%
2 PM
80°
3%
3 PM
81°
3%
4 PM
80°
3%
5 PM
82°
3%
6 PM
80°
3%
7 PM
78°
3%
8 PM
76°
3%
9 PM
72°
3%
10 PM
71°
5%
11 PM
69°
5%
12 AM
68°
5%
1 AM
68°
17%
2 AM
67°
21%
3 AM
67°
9%
4 AM
67°
9%
5 AM
63°
9%
6 AM
63°
9%
7 AM
65°
16%
8 AM
68°
17%
9 AM
69°
17%
10 AM
70°
32%
11 AM
71°
33%
12 PM
72°
33%
7-Day Forecast
Today
82° 61°
Partly Cloudy.
Wed
84° 63°
Drizzle, 46% chance.
Thu
87° 68°
Heavy Rain, 90% chance.
Fri
86° 68°
Heavy Rain, 90% chance.
Sat
94° 71°
Drizzle, 62% chance.
Sun
98° 73°
Thunderstorm, 47% chance.
Mon
99° 74°
Clear.
TimeTempConditionsPrecipWindHumidity
Now 79° Clear 3% 3 mph E 49%
2 PM 80° Mostly Clear 3% 3 mph ENE 48%
3 PM 81° Partly Cloudy 3% 3 mph NE 49%
4 PM 80° Mostly Cloudy 3% 3 mph ENE 51%
5 PM 82° Partly Cloudy 3% 4 mph E 54%
6 PM 80° Partly Cloudy 3% 4 mph E 59%
7 PM 78° Overcast 3% 4 mph E 64%
8 PM 76° Overcast 3% 4 mph E 67%
9 PM 72° Overcast 3% 4 mph E 69%
10 PM 71° Overcast 5% 4 mph ESE 72%
11 PM 69° Overcast 5% 4 mph ESE 74%
12 AM 68° Overcast 5% 4 mph SE 75%
1 AM 68° Overcast 17% 4 mph SSE 75%
2 AM 67° Overcast 21% 5 mph SSE 75%
3 AM 67° Overcast 9% 5 mph SSE 75%
4 AM 67° Overcast 9% 5 mph SSE 75%
5 AM 63° Overcast 9% 5 mph SE 76%
6 AM 63° Overcast 9% 5 mph SSE 76%
7 AM 65° Overcast 16% 6 mph SSE 73%
8 AM 68° Overcast 17% 6 mph S 72%
9 AM 69° Overcast 17% 7 mph S 70%
10 AM 70° Drizzle 32% 7 mph S 70%
11 AM 71° Drizzle 33% 7 mph S 69%
12 PM 72° Drizzle 33% 7 mph S 68%
15-Day Forecast
Today
6/23
Partly Cloudy
5%
61°
82°
Wed
6/24
Drizzle
46%
63°
84°
Thu
6/25
Heavy Rain
90%
68°
87°
Fri
6/26
Heavy Rain
90%
68°
86°
Sat
6/27
Drizzle
62%
71°
94°
Sun
6/28
Thunderstorm
47%
73°
98°
Mon
6/29
Clear
9%
74°
99°
Tue
6/30
Thunderstorm
46%
75°
100°
Wed
7/1
Thunderstorm
63%
75°
100°
Thu
7/2
Drizzle
63%
73°
92°
Fri
7/3
Drizzle
63%
75°
93°
Sat
7/4
Drizzle
66%
71°
92°
Sun
7/5
Drizzle
66%
70°
91°
Mon
7/6
Drizzle
66%
70°
93°
Tue
7/7
Drizzle
66%
69°
91°
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, 17:00'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
SBCAPE40 J/kg
MLCAPE7 J/kg
MUCAPE40 J/kg
SBCIN0 J/kg
MLCIN0 J/kg
Lifted Index2.7
Kinematics
0–6 km Shear32 kt
0–1 km Shear4 kt
Eff. Shear—
0–1 km SRH12
0–3 km SRH-113
Eff. SRH—
Storm Motion259° @ 19 kt
0–1 km EHI0.0
Composite Parameters
Sig. Tornado0.0
STP (eff)—
Supercell—
K-Index15.0
Thermo & Levels
PWAT0.94 in
0–3 km LR6.6 °C/km
700–500 LR5.5 °C/km
Total Totals33.9
LCL848 hPa
LFC1002 hPa
EL819 hPa
Freezing Lvl13,340 ft