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

Jefferson County, Missouri, United States

Last updated: 3:50 AM CDT  ·  Refresh
24°C
Feels like 28°
Partly Cloudy
▲ 33°  /  ▼ 22°
Wind
3 mph W
Humidity
85%
Dew Point
22°
Pressure
29.24 inHg
Visibility
10 mi
UV Index
0.0
Cloud Cover
51%
Sunrise
5:54 AM
Sunset
8:22 PM
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WeatherAI™ Analysis

WeatherAI Analysis: Jefferson County is currently partly cloudy at 24°C. Precipitation is likely — peak probability 76% around 2 PM. Atmospheric instability is elevated (CAPE up to 2285 J/kg) — isolated convective development possible. Sunrise: 5:54AM · 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
44 AQI · Good Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
24°
8%
4 AM
24°
20%
5 AM
22°
20%
6 AM
22°
20%
7 AM
24°
30%
8 AM
26°
33%
9 AM
29°
44%
10 AM
31°
52%
11 AM
31°
52%
12 PM
32°
56%
1 PM
32°
70%
2 PM
31°
76%
3 PM
30°
76%
4 PM
29°
72%
5 PM
28°
58%
6 PM
28°
46%
7 PM
27°
46%
8 PM
27°
35%
9 PM
24°
34%
10 PM
24°
25%
11 PM
24°
22%
12 AM
24°
11%
1 AM
23°
11%
2 AM
23°
16%
7-Day Forecast
Today
33° 22°
Partly Cloudy with a 76% chance of rain.
Mon
36° 22°
Mostly Clear with a 20% chance of rain.
Tue
39° 22°
Mostly Clear with a 31% chance of rain.
Wed
29° 17°
Clear.
Thu
29° 16°
Clear.
Fri
30° 16°
Heavy Rain, 82% chance.
Sat
31° 15°
Drizzle, 53% chance.
TimeTempConditionsPrecipWindHumidity
Now 24° Partly Cloudy 8% 3 mph W 85%
4 AM 24° Mostly Cloudy 20% 4 mph W 87%
5 AM 22° Partly Cloudy 20% 4 mph W 87%
6 AM 22° Mostly Clear 20% 4 mph W 87%
7 AM 24° Mostly Clear 30% 5 mph WNW 82%
8 AM 26° Mostly Clear 33% 4 mph WNW 76%
9 AM 29° Clear 44% 4 mph NW 70%
10 AM 31° Mostly Clear 52% 4 mph NW 67%
11 AM 31° Partly Cloudy 52% 4 mph NW 64%
12 PM 32° Mostly Cloudy 56% 3 mph NW 62%
1 PM 32° Mostly Cloudy 70% 4 mph NW 65%
2 PM 31° Rain 76% 5 mph N 69%
3 PM 30° Mostly Cloudy 76% 6 mph E 74%
4 PM 29° Mostly Cloudy 72% 5 mph ENE 79%
5 PM 28° Mostly Cloudy 58% 3 mph ENE 83%
6 PM 28° Partly Cloudy 46% 3 mph ESE 88%
7 PM 27° Partly Cloudy 46% 3 mph ESE 90%
8 PM 27° Partly Cloudy 35% 2 mph ESE 91%
9 PM 24° Partly Cloudy 34% 2 mph ESE 92%
10 PM 24° Partly Cloudy 25% 2 mph E 94%
11 PM 24° Partly Cloudy 22% 2 mph E 95%
12 AM 24° Partly Cloudy 11% 2 mph E 96%
1 AM 23° Partly Cloudy 11% 2 mph E 97%
2 AM 23° Partly Cloudy 16% 2 mph E 97%
15-Day Forecast
Today
7/19
Partly Cloudy
76%
22°
33°
Mon
7/20
Mostly Clear
20%
22°
36°
Tue
7/21
Mostly Clear
31%
22°
39°
Wed
7/22
Clear
16%
17°
29°
Thu
7/23
Clear
16%
16°
29°
Fri
7/24
Heavy Rain
82%
16°
30°
Sat
7/25
Drizzle
53%
15°
31°
Sun
7/26
Clear
43%
17°
34°
Mon
7/27
Thunderstorm
44%
18°
37°
Tue
7/28
Thunderstorm
51%
23°
36°
Wed
7/29
Drizzle
60%
22°
35°
Thu
7/30
Drizzle
60%
22°
36°
Fri
7/31
Drizzle
60%
22°
37°
Sat
8/1
Drizzle
60%
22°
36°
Sun
8/2
Clear
60%
22°
36°
44
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
44 AQI 8.0 µg/m³
O3
Ground-level ozone
25 AQI 27 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Today 44 Good 25 44
Mon 61 Moderate 44 61
Tue 88 Moderate 30 88
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
SBCAPE503 J/kg
MLCAPE608 J/kg
MUCAPE977 J/kg
SBCIN-165 J/kg
MLCIN0 J/kg
Lifted Index-1.9
Kinematics
0–6 km Shear9 kt
0–1 km Shear12 kt
Eff. Shear9 kt
0–1 km SRH8
0–3 km SRH4
Eff. SRH4
Storm Motion293° @ 22 kt
0–1 km EHI0.0
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index35.4
Thermo & Levels
PWAT1.92 in
0–3 km LR4.8 °C/km
700–500 LR5.6 °C/km
Total Totals44.5
LCL957 hPa
LFC787 hPa
EL221 hPa
Freezing Lvl15,810 ft