Extreme Heat Warning — Jefferson, IL, Wayne, IL, Edwards, IL, Wabash, IL, Perry, IL, Franklin, IL, Hamilton, IL, White, IL, Jackson, IL, Williamson, IL, Saline, IL, Gallatin, IL, Union, IL, Johnson, IL, Pope, IL, Hardin, IL, Alexander, IL, Pulaski, IL, Massac, IL, Gibson, IN, Pike, IN, Posey, IN, Vanderburgh, IN, Warrick, IN, Spencer, IN, Fulton, KY, Hickman, KY, Carlisle, KY, Ballard, KY, McCracken, KY, Graves, KY, Livingston, KY, Marshall, KY, Calloway, KY, Crittenden, KY, Lyon, KY, Trigg, KY, Caldwell, KY, Union, KY, Webster, KY, Hopkins, KY, Christian, KY, Henderson, KY, Daviess, KY, McLean, KY, Muhlenberg, KY, Todd, KY, Perry, MO, Bollinger, MO, Cape Girardeau, MO, Wayne, MO, Carter, MO, Ripley, MO, Butler, MO, Stoddard, MO, Scott, MO, Mississippi, MO, New Madrid, MO 8:00 PM

Jefferson County, Illinois, United States

Last updated: 2:26 AM CDT  ·  Refresh
26°C
Feels like 28°
Clear
▲ 38°  /  ▼ 23°
Wind
3 mph S
Humidity
74%
Dew Point
21°
Pressure
29.44 inHg
Visibility
10 mi
UV Index
0.0
Cloud Cover
7%
Sunrise
6:27 AM
Sunset
7:20 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Jefferson County is currently clear at 25°C. Dry conditions are expected through the next 24 hours. Atmospheric instability is elevated (CAPE up to 1615 J/kg) — isolated convective development possible. Sunrise: 6:27AM · Sunset: 7:20PM.

Alerts

Extreme Heat Warning
Jefferson, IL, Wayne, IL, Edwards, IL, Wabash, IL, Perry, IL, Franklin, IL, Hamilton, IL, White, IL, Jackson, IL, Williamson, IL, Saline, IL, Gallatin, IL, Union, IL, Johnson, IL, Pope, IL, Hardin, IL, Alexander, IL, Pulaski, IL, Massac, IL, Gibson, IN, Pike, IN, Posey, IN, Vanderburgh, IN, Warrick, IN, Spencer, IN, Fulton, KY, Hickman, KY, Carlisle, KY, Ballard, KY, McCracken, KY, Graves, KY, Livingston, KY, Marshall, KY, Calloway, KY, Crittenden, KY, Lyon, KY, Trigg, KY, Caldwell, KY, Union, KY, Webster, KY, Hopkins, KY, Christian, KY, Henderson, KY, Daviess, KY, McLean, KY, Muhlenberg, KY, Todd, KY, Perry, MO, Bollinger, MO, Cape Girardeau, MO, Wayne, MO, Carter, MO, Ripley, MO, Butler, MO, Stoddard, MO, Scott, MO, Mississippi, MO, New Madrid, MO
Expires 8:00 PM
53 AQI · Moderate Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
26°
10%
3 AM
25°
4%
4 AM
25°
4%
5 AM
23°
4%
6 AM
23°
3%
7 AM
23°
3%
8 AM
27°
3%
9 AM
31°
3%
10 AM
33°
11%
11 AM
34°
11%
12 PM
34°
11%
1 PM
37°
11%
2 PM
37°
11%
3 PM
38°
14%
4 PM
37°
14%
5 PM
38°
14%
6 PM
37°
14%
7 PM
36°
14%
8 PM
34°
15%
9 PM
29°
15%
10 PM
28°
9%
11 PM
28°
9%
12 AM
28°
9%
1 AM
28°
9%
7-Day Forecast
Today
38° 23°
Clear.
Sat
41° 23°
Mostly Clear with a 26% chance of rain.
Sun
36° 17°
Mostly Clear.
Mon
33° 12°
Partly Cloudy.
Tue
39° 16°
Clear.
Wed
41° 22°
Drizzle, 43% chance.
Thu
38° 18°
Clear with a 31% chance of rain.
TimeTempConditionsPrecipWindHumidity
Now 26° Clear 10% 3 mph S 74%
3 AM 25° Mostly Clear 4% 4 mph S 74%
4 AM 25° Mostly Clear 4% 4 mph S 76%
5 AM 23° Clear 4% 4 mph S 77%
6 AM 23° Clear 3% 4 mph SSW 78%
7 AM 23° Clear 3% 3 mph SSW 76%
8 AM 27° Clear 3% 4 mph SW 67%
9 AM 31° Clear 3% 5 mph WSW 58%
10 AM 33° Clear 11% 6 mph WSW 50%
11 AM 34° Clear 11% 6 mph WSW 45%
12 PM 34° Clear 11% 7 mph WSW 42%
1 PM 37° Clear 11% 7 mph WSW 39%
2 PM 37° Clear 11% 7 mph WSW 38%
3 PM 38° Clear 14% 7 mph WSW 37%
4 PM 37° Clear 14% 7 mph WSW 38%
5 PM 38° Clear 14% 6 mph WSW 42%
6 PM 37° Clear 14% 5 mph SW 46%
7 PM 36° Clear 14% 5 mph SSW 51%
8 PM 34° Mostly Clear 15% 5 mph SSW 55%
9 PM 29° Mostly Clear 15% 5 mph SSW 59%
10 PM 28° Mostly Clear 9% 6 mph S 61%
11 PM 28° Mostly Clear 9% 5 mph SSW 63%
12 AM 28° Clear 9% 6 mph SSW 64%
1 AM 28° Clear 9% 6 mph SSW 65%
15-Day Forecast
Today
9/4
Clear
15%
23°
38°
Sat
9/5
Mostly Clear
26%
23°
41°
Sun
9/6
Mostly Clear
13%
17°
36°
Mon
9/7
Partly Cloudy
7%
12°
33°
Tue
9/8
Clear
3%
16°
39°
Wed
9/9
Drizzle
43%
22°
41°
Thu
9/10
Clear
31%
18°
38°
Fri
9/11
Rain
44%
14°
37°
Sat
9/12
Clear
19%
21°
40°
Sun
9/13
Clear
44%
16°
37°
Mon
9/14
Clear
60%
21°
38°
Tue
9/15
Drizzle
60%
22°
38°
Wed
9/16
Drizzle
60%
21°
37°
Thu
9/17
Drizzle
60%
19°
34°
Fri
9/18
Clear
25%
18°
34°
53
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
53 AQI 10.2 µg/m³
O3
Ground-level ozone
42 AQI 45 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Today 53 Moderate 42 53
Sat 54 Moderate 47 54
Sun 52 Moderate 46 52
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 Fri Sep 4, 06:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE249 J/kg
MLCAPE434 J/kg
MUCAPE542 J/kg
SBCIN-472 J/kg
MLCIN-207 J/kg
Lifted Index-1.4
Kinematics
0–6 km Shear8 kt
0–1 km Shear14 kt
Eff. Shear8 kt
0–1 km SRH32
0–3 km SRH20
Eff. SRH4
Storm Motion347° @ 8 kt
0–1 km EHI0.1
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index39.8
Thermo & Levels
PWAT1.65 in
0–3 km LR5.4 °C/km
700–500 LR5.3 °C/km
Total Totals48.1
LCL937 hPa
LFC544 hPa
EL282 hPa
Freezing Lvl16,493 ft