Excessive Heat Watch 12:00 AM Heat Advisory — Knox, MO, Lewis, MO, Shelby, MO, Marion, MO, Monroe, MO, Ralls, MO, Pike, MO, Boone, MO, Audrain, MO, Moniteau, MO, Cole, MO, Osage, MO, Callaway, MO, Montgomery, MO, Lincoln, MO, Gasconade, MO, Crawford, MO, Washington, MO, St. Francois, MO, Iron, MO, Madison, MO, Reynolds, MO, Warren, MO, St. Charles, MO, Franklin, MO, St. Louis, MO, St. Louis City, MO, Jefferson, MO, Ste. Genevieve, MO 10:00 PM Excessive Heat Warning — 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, Ste. Genevieve, MO, Knox, MO, Lewis, MO, Shelby, MO, Marion, MO, Monroe, MO, Ralls, MO, Pike, MO, Audrain, MO, Lincoln, MO, Crawford, MO, Washington, MO, St. Francois, MO, Iron, MO, Madison, MO, Reynolds, MO 8:00 PM

Saint Louis, Missouri

Last updated: 6:56 PM CDT  ·  Refresh
33°C
Feels like 38°
Mostly Clear
▲ 36°  /  ▼ 23°
Wind
8 mph S
Humidity
59%
Dew Point
23°
Pressure
29.52 inHg
Visibility
10 mi
UV Index
3.9
Cloud Cover
20%
Sunrise
5:40 AM
Sunset
8:29 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Saint Louis is currently mostly clear at 33°C. Dry conditions are expected through the next 24 hours. Atmospheric instability is elevated (CAPE up to 3166 J/kg) — isolated convective development possible. Sunrise: 5:40AM · Sunset: 8:29PM.

Alerts

Excessive Heat Watch
Expires 12:00 AM
Heat Advisory
Knox, MO, Lewis, MO, Shelby, MO, Marion, MO, Monroe, MO, Ralls, MO, Pike, MO, Boone, MO, Audrain, MO, Moniteau, MO, Cole, MO, Osage, MO, Callaway, MO, Montgomery, MO, Lincoln, MO, Gasconade, MO, Crawford, MO, Washington, MO, St. Francois, MO, Iron, MO, Madison, MO, Reynolds, MO, Warren, MO, St. Charles, MO, Franklin, MO, St. Louis, MO, St. Louis City, MO, Jefferson, MO, Ste. Genevieve, MO
Expires 10:00 PM
Excessive Heat Warning
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, Ste. Genevieve, MO, Knox, MO, Lewis, MO, Shelby, MO, Marion, MO, Monroe, MO, Ralls, MO, Pike, MO, Audrain, MO, Lincoln, MO, Crawford, MO, Washington, MO, St. Francois, MO, Iron, MO, Madison, MO, Reynolds, MO
Expires 8:00 PM
63 AQI · Moderate Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
33°
30%
7 PM
31°
46%
8 PM
30°
47%
9 PM
28°
27%
10 PM
28°
23%
11 PM
27°
16%
12 AM
27°
12%
1 AM
26°
7%
2 AM
25°
8%
3 AM
24°
8%
4 AM
25°
8%
5 AM
23°
8%
6 AM
24°
8%
7 AM
26°
22%
8 AM
27°
23%
9 AM
29°
31%
10 AM
31°
31%
11 AM
32°
28%
12 PM
33°
29%
1 PM
34°
36%
2 PM
34°
40%
3 PM
34°
40%
4 PM
33°
36%
5 PM
32°
33%
7-Day Forecast
Tonight
36° 23°
Mostly Clear with a 30% chance of rain.
Fri
36° 23°
Mostly Clear with a 31% chance of rain.
Sat
36° 24°
Mostly Clear with a 55% chance of rain.
Sun
33° 21°
Rain, 64% chance.
Mon
32° 21°
Fog with a 37% chance of rain.
Tue
32° 20°
Drizzle, 59% chance.
Wed
32° 21°
Drizzle, 52% chance.
TimeTempConditionsPrecipWindHumidity
Now 33° Mostly Clear 30% 8 mph S 59%
7 PM 31° Partly Cloudy 46% 7 mph S 66%
8 PM 30° Partly Cloudy 47% 7 mph S 70%
9 PM 28° Mostly Cloudy 27% 7 mph S 74%
10 PM 28° Partly Cloudy 23% 6 mph SSW 74%
11 PM 27° Partly Cloudy 16% 5 mph SSW 75%
12 AM 27° Partly Cloudy 12% 5 mph SSW 75%
1 AM 26° Partly Cloudy 7% 4 mph SSW 77%
2 AM 25° Mostly Cloudy 8% 4 mph SSW 79%
3 AM 24° Partly Cloudy 8% 4 mph S 82%
4 AM 25° Mostly Clear 8% 4 mph S 83%
5 AM 23° Mostly Clear 8% 4 mph S 83%
6 AM 24° Clear 8% 4 mph S 84%
7 AM 26° Clear 22% 5 mph SSW 78%
8 AM 27° Mostly Clear 23% 5 mph SSW 72%
9 AM 29° Mostly Clear 31% 6 mph SSW 66%
10 AM 31° Mostly Clear 31% 6 mph SSW 60%
11 AM 32° Mostly Clear 28% 6 mph SSW 54%
12 PM 33° Mostly Clear 29% 7 mph SSW 49%
1 PM 34° Partly Cloudy 36% 7 mph S 51%
2 PM 34° Partly Cloudy 40% 7 mph S 52%
3 PM 34° Partly Cloudy 40% 7 mph S 54%
4 PM 33° Mostly Clear 36% 7 mph S 57%
5 PM 32° Mostly Clear 33% 6 mph S 59%
15-Day Forecast
Today
7/2
Mostly Clear
30%
23°
36°
Fri
7/3
Mostly Clear
31%
23°
36°
Sat
7/4
Mostly Clear
55%
24°
36°
Sun
7/5
Rain
64%
21°
33°
Mon
7/6
Fog
37%
21°
32°
Tue
7/7
Drizzle
59%
20°
32°
Wed
7/8
Drizzle
52%
21°
32°
Thu
7/9
Rain
63%
23°
33°
Fri
7/10
Rain
68%
22°
32°
Sat
7/11
Drizzle
68%
22°
33°
Sun
7/12
Drizzle
64%
20°
31°
Mon
7/13
Drizzle
60%
19°
30°
Tue
7/14
Drizzle
60%
19°
30°
Wed
7/15
Drizzle
60%
19°
31°
Thu
7/16
Drizzle
60%
20°
32°
63
Moderate
U.S. Air Quality Index · Dominant: PM2.5
50 100 150 200

Air quality is acceptable. Unusually sensitive people should consider limiting prolonged outdoor exertion.

Pollutant Breakdown · Today
PM2.5
Fine particulate matter
Dominant
63 AQI 15.9 µg/m³
O3
Ground-level ozone
39 AQI 42 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Fri 63 Moderate 39 63
Sat 65 Moderate 36 65
Sun 68 Moderate 35 68
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 Thu Jul 2, 22:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE2774 J/kg
MLCAPE2433 J/kg
MUCAPE2774 J/kg
SBCIN-89 J/kg
MLCIN0 J/kg
Lifted Index-5.8
Kinematics
0–6 km Shear10 kt
0–1 km Shear7 kt
Eff. Shear9 kt
0–1 km SRH-11
0–3 km SRH-42
Eff. SRH-42
Storm Motion193° @ 28 kt
0–1 km EHI-0.2
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index34.5
Thermo & Levels
PWAT1.87 in
0–3 km LR7.2 °C/km
700–500 LR6.0 °C/km
Total Totals49.7
LCL864 hPa
LFC809 hPa
EL149 hPa
Freezing Lvl15,371 ft