Extreme Heat Warning — Clinton, IL, Washington, IL, Randolph, IL, Madison, IL, St. Clair, IL, Monroe, IL, Boone, MO, Moniteau, MO, Cole, MO, Osage, MO, Callaway, MO, Montgomery, MO, Gasconade, MO, Warren, MO, St. Charles, MO, Franklin, MO, St. Louis, MO, St. Louis City, MO, Jefferson, MO 8:00 PM

Saint Louis, Missouri

Last updated: 5:17 AM CDT  ·  Refresh
26°C
Feels like 28°
Mostly Clear
▲ 36°  /  ▼ 26°
Wind
6 mph SSW
Humidity
74%
Dew Point
22°
Pressure
29.46 inHg
Visibility
9 mi
UV Index
0.0
Cloud Cover
20%
Sunrise
6:11 AM
Sunset
7:59 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Saint Louis is currently mostly clear at 26°C. Dry conditions are expected through the next 24 hours. Atmospheric instability is elevated (CAPE up to 2681 J/kg) — isolated convective development possible. Sunrise: 6:11AM · Sunset: 7:59PM.

Alerts

Extreme Heat Warning
Clinton, IL, Washington, IL, Randolph, IL, Madison, IL, St. Clair, IL, Monroe, IL, Boone, MO, Moniteau, MO, Cole, MO, Osage, MO, Callaway, MO, Montgomery, MO, Gasconade, MO, Warren, MO, St. Charles, MO, Franklin, MO, St. Louis, MO, St. Louis City, MO, Jefferson, MO
Expires 8:00 PM
45 AQI · Good Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
26°
4%
6 AM
24°
21%
7 AM
25°
20%
8 AM
26°
20%
9 AM
28°
20%
10 AM
29°
14%
11 AM
31°
14%
12 PM
33°
14%
1 PM
35°
3%
2 PM
36°
3%
3 PM
36°
4%
4 PM
36°
4%
5 PM
36°
5%
6 PM
35°
5%
7 PM
34°
5%
8 PM
32°
13%
9 PM
31°
13%
10 PM
29°
14%
11 PM
29°
22%
12 AM
27°
23%
1 AM
27°
23%
2 AM
27°
24%
3 AM
27°
15%
4 AM
27°
15%
7-Day Forecast
Today
36° 26°
Partly Cloudy with a 22% chance of rain.
Wed
37° 26°
Partly Cloudy with a 47% chance of rain.
Thu
35° 25°
Mostly Clear with a 42% chance of rain.
Fri
34° 23°
Clear with a 32% chance of rain.
Sat
38° 24°
Mostly Clear.
Sun
38° 23°
Drizzle, 49% chance.
Mon
32° 22°
Mostly Cloudy with a 39% chance of rain.
TimeTempConditionsPrecipWindHumidity
Now 26° Mostly Clear 4% 6 mph SSW 74%
6 AM 24° Mostly Clear 21% 7 mph SSW 70%
7 AM 25° Mostly Clear 20% 8 mph SW 69%
8 AM 26° Mostly Clear 20% 8 mph SW 64%
9 AM 28° Mostly Clear 20% 9 mph SW 60%
10 AM 29° Partly Cloudy 14% 10 mph SW 54%
11 AM 31° Mostly Clear 14% 10 mph WSW 50%
12 PM 33° Mostly Clear 14% 11 mph WSW 45%
1 PM 35° Partly Cloudy 3% 11 mph WSW 41%
2 PM 36° Partly Cloudy 3% 11 mph SW 39%
3 PM 36° Partly Cloudy 4% 11 mph SW 38%
4 PM 36° Partly Cloudy 4% 10 mph SW 38%
5 PM 36° Partly Cloudy 5% 9 mph SW 40%
6 PM 35° Partly Cloudy 5% 8 mph SW 44%
7 PM 34° Mostly Cloudy 5% 7 mph SW 47%
8 PM 32° Mostly Cloudy 13% 6 mph SSW 50%
9 PM 31° Partly Cloudy 13% 6 mph SSW 53%
10 PM 29° Partly Cloudy 14% 6 mph SSW 56%
11 PM 29° Partly Cloudy 22% 6 mph SSW 60%
12 AM 27° Partly Cloudy 23% 6 mph SSW 63%
1 AM 27° Partly Cloudy 23% 6 mph S 65%
2 AM 27° Partly Cloudy 24% 6 mph SSW 66%
3 AM 27° Partly Cloudy 15% 6 mph SSW 68%
4 AM 27° Partly Cloudy 15% 6 mph SSW 69%
15-Day Forecast
Today
8/11
Partly Cloudy
22%
26°
36°
Wed
8/12
Partly Cloudy
47%
26°
37°
Thu
8/13
Mostly Clear
42%
25°
35°
Fri
8/14
Clear
32%
23°
34°
Sat
8/15
Mostly Clear
15%
24°
38°
Sun
8/16
Drizzle
49%
23°
38°
Mon
8/17
Mostly Cloudy
39%
22°
32°
Tue
8/18
Rain
53%
21°
36°
Wed
8/19
Mostly Cloudy
35%
23°
38°
Thu
8/20
Mostly Clear
35%
24°
38°
Fri
8/21
Drizzle
60%
20°
38°
Sat
8/22
Drizzle
60%
21°
34°
Sun
8/23
Clear
60%
21°
34°
Mon
8/24
Drizzle
60%
20°
32°
Tue
8/25
Drizzle
60%
19°
32°
45
Good
U.S. Air Quality Index · Dominant: PM2.5
50 100 150 200

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

Pollutant Breakdown · Today
PM2.5
Fine particulate matter
Dominant
45 AQI 8.1 µg/m³
O3
Ground-level ozone
41 AQI 45 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Today 45 Good 41 45
Wed 41 Good 41 27
Thu 42 Good 42 37
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 Aug 11, 09:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE1816 J/kg
MLCAPE1393 J/kg
MUCAPE1816 J/kg
SBCIN-400 J/kg
MLCIN0 J/kg
Lifted Index-7.3
Kinematics
0–6 km Shear21 kt
0–1 km Shear20 kt
Eff. Shear17 kt
0–1 km SRH165
0–3 km SRH153
Eff. SRH-14
Storm Motion313° @ 17 kt
0–1 km EHI1.9
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index29.5
Thermo & Levels
PWAT1.63 in
0–3 km LR4.3 °C/km
700–500 LR8.4 °C/km
Total Totals56.5
LCL945 hPa
LFC665 hPa
EL179 hPa
Freezing Lvl14,721 ft