Heat Advisory — 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, Crawford, MO, Washington, MO, St. Francois, MO, Ste. Genevieve, MO, Iron, MO, Madison, MO, Reynolds, MO 7:00 PM

Saint Louis, Missouri

Last updated: 3:49 AM CDT  ·  Refresh
26°C
Feels like 31°
Mostly Cloudy
▲ 32°  /  ▼ 22°
Wind
3 mph W
Humidity
84%
Dew Point
23°
Pressure
29.44 inHg
Visibility
10 mi
UV Index
0.0
Cloud Cover
73%
Sunrise
5:51 AM
Sunset
8:22 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Saint Louis is currently mostly cloudy at 26°C. Precipitation is likely — peak probability 77% around 1 PM. Atmospheric instability is elevated (CAPE up to 2171 J/kg) — isolated convective development possible. Sunrise: 5:51AM · Sunset: 8:22PM.

Alerts

Heat Advisory
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, Crawford, MO, Washington, MO, St. Francois, MO, Ste. Genevieve, MO, Iron, MO, Madison, MO, Reynolds, MO
Expires 7:00 PM
55 AQI · Moderate Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
26°
12%
4 AM
26°
16%
5 AM
24°
15%
6 AM
24°
15%
7 AM
26°
29%
8 AM
27°
34%
9 AM
29°
54%
10 AM
30°
68%
11 AM
30°
75%
12 PM
31°
72%
1 PM
31°
76%
2 PM
31°
69%
3 PM
31°
74%
4 PM
29°
63%
5 PM
30°
63%
6 PM
29°
51%
7 PM
29°
52%
8 PM
28°
53%
9 PM
27°
45%
10 PM
26°
45%
11 PM
25°
32%
12 AM
24°
15%
1 AM
24°
9%
2 AM
24°
9%
7-Day Forecast
Today
32° 22°
Partly Cloudy with a 74% chance of rain.
Mon
34° 22°
Mostly Clear.
Tue
37° 22°
Clear.
Wed
28° 18°
Clear.
Thu
27° 17°
Clear.
Fri
27° 16°
Rain, 82% chance.
Sat
28° 16°
Clear with a 52% chance of rain.
TimeTempConditionsPrecipWindHumidity
Now 26° Mostly Cloudy 12% 3 mph W 84%
4 AM 26° Partly Cloudy 16% 3 mph W 84%
5 AM 24° Mostly Clear 15% 3 mph W 85%
6 AM 24° Partly Cloudy 15% 3 mph WNW 85%
7 AM 26° Mostly Clear 29% 2 mph NNW 81%
8 AM 27° Mostly Clear 34% 3 mph N 76%
9 AM 29° Mostly Clear 54% 3 mph NNE 72%
10 AM 30° Mostly Clear 68% 3 mph NNE 70%
11 AM 30° Partly Cloudy 75% 4 mph NNE 70%
12 PM 31° Partly Cloudy 72% 6 mph NE 69%
1 PM 31° Partly Cloudy 76% 6 mph NE 72%
2 PM 31° Partly Cloudy 69% 6 mph NE 75%
3 PM 31° Partly Cloudy 74% 5 mph ENE 77%
4 PM 29° Partly Cloudy 63% 6 mph E 77%
5 PM 30° Partly Cloudy 63% 6 mph E 78%
6 PM 29° Rain 51% 6 mph E 78%
7 PM 29° Rain 52% 5 mph E 81%
8 PM 28° Rain 53% 5 mph E 84%
9 PM 27° Rain 45% 5 mph E 87%
10 PM 26° Partly Cloudy 45% 4 mph E 88%
11 PM 25° Partly Cloudy 32% 5 mph E 88%
12 AM 24° Mostly Clear 15% 5 mph E 88%
1 AM 24° Mostly Clear 9% 5 mph E 88%
2 AM 24° Mostly Clear 9% 5 mph E 88%
15-Day Forecast
Today
7/19
Partly Cloudy
74%
22°
32°
Mon
7/20
Mostly Clear
10%
22°
34°
Tue
7/21
Clear
10%
22°
37°
Wed
7/22
Clear
8%
18°
28°
Thu
7/23
Clear
16%
17°
27°
Fri
7/24
Rain
82%
16°
27°
Sat
7/25
Clear
52%
16°
28°
Sun
7/26
Clear
43%
17°
32°
Mon
7/27
Rain
68%
19°
34°
Tue
7/28
Thunderstorm
51%
23°
34°
Wed
7/29
Drizzle
60%
21°
33°
Thu
7/30
Drizzle
60%
21°
33°
Fri
7/31
Drizzle
60%
22°
33°
Sat
8/1
Drizzle
60%
22°
33°
Sun
8/2
Drizzle
60%
22°
33°
55
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
55 AQI 11.4 µg/m³
O3
Ground-level ozone
31 AQI 33 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Today 55 Moderate 31 55
Mon 81 Moderate 44 81
Tue 152 Unhealthy 47 152
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 Sun Jul 19, 07:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE1437 J/kg
MLCAPE1039 J/kg
MUCAPE1437 J/kg
SBCIN-75 J/kg
MLCIN0 J/kg
Lifted Index-3.9
Kinematics
0–6 km Shear10 kt
0–1 km Shear11 kt
Eff. Shear11 kt
0–1 km SRH-20
0–3 km SRH-31
Eff. SRH-31
Storm Motion281° @ 21 kt
0–1 km EHI-0.2
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index37.7
Thermo & Levels
PWAT2.20 in
0–3 km LR5.4 °C/km
700–500 LR5.5 °C/km
Total Totals45.8
LCL957 hPa
LFC833 hPa
EL185 hPa
Freezing Lvl15,948 ft