Heat Advisory — Jefferson, IL, Perry, IL, Franklin, IL, Jackson, IL, Williamson, IL, Union, IL, Johnson, IL, Pope, IL, Alexander, IL, Pulaski, IL, Massac, IL, Fulton, KY, Hickman, KY, Carlisle, KY, Ballard, KY, McCracken, KY, Graves, KY, Livingston, KY, Marshall, KY, Calloway, 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 7:00 PM

Jefferson County, Illinois, United States

Last updated: 12:14 PM CDT  ·  Refresh
31°C
Feels like 41°
Partly Cloudy
▲ 36°  /  ▼ 23°
Wind
5 mph SSW
Humidity
78%
Dew Point
27°
Pressure
29.42 inHg
Visibility
10 mi
UV Index
9.2
Cloud Cover
36%
Sunrise
5:53 AM
Sunset
8:10 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Jefferson County is currently partly cloudy at 31°C. Precipitation is likely — peak probability 62% around 11 PM. Atmospheric instability is elevated (CAPE up to 4426 J/kg) — isolated convective development possible. Sunrise: 5:53AM · Sunset: 8:10PM.

Alerts

Heat Advisory
Jefferson, IL, Perry, IL, Franklin, IL, Jackson, IL, Williamson, IL, Union, IL, Johnson, IL, Pope, IL, Alexander, IL, Pulaski, IL, Massac, IL, Fulton, KY, Hickman, KY, Carlisle, KY, Ballard, KY, McCracken, KY, Graves, KY, Livingston, KY, Marshall, KY, Calloway, 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 7:00 PM
54 AQI · Moderate Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
31°
17%
1 PM
33°
41%
2 PM
34°
44%
3 PM
34°
43%
4 PM
35°
42%
5 PM
36°
37%
6 PM
35°
41%
7 PM
34°
42%
8 PM
33°
56%
9 PM
30°
61%
10 PM
29°
61%
11 PM
28°
61%
12 AM
26°
42%
1 AM
25°
29%
2 AM
24°
29%
3 AM
24°
30%
4 AM
24°
30%
5 AM
23°
16%
6 AM
23°
12%
7 AM
24°
3%
8 AM
26°
10%
9 AM
28°
10%
10 AM
29°
10%
11 AM
30°
10%
7-Day Forecast
Today
36° 23°
Partly Cloudy with a 61% chance of rain.
Mon
36° 23°
Partly Cloudy with a 42% chance of rain.
Tue
34° 21°
Mostly Clear with a 42% chance of rain.
Wed
30° 18°
Clear with a 62% chance of rain.
Thu
31° 18°
Clear with a 44% chance of rain.
Fri
28° 19°
Rain, 90% chance.
Sat
29° 18°
Drizzle, 81% chance.
TimeTempConditionsPrecipWindHumidity
Now 31° Partly Cloudy 17% 5 mph SSW 78%
1 PM 33° Partly Cloudy 41% 7 mph SW 74%
2 PM 34° Partly Cloudy 44% 8 mph SW 71%
3 PM 34° Partly Cloudy 43% 9 mph WSW 68%
4 PM 35° Mostly Clear 42% 8 mph WSW 66%
5 PM 36° Mostly Clear 37% 6 mph WSW 66%
6 PM 35° Mostly Clear 41% 5 mph WSW 70%
7 PM 34° Mostly Clear 42% 5 mph SW 74%
8 PM 33° Mostly Clear 56% 4 mph SSW 77%
9 PM 30° Partly Cloudy 61% 5 mph SSW 80%
10 PM 29° Partly Cloudy 61% 5 mph SSW 82%
11 PM 28° Mostly Cloudy 61% 3 mph SSE 87%
12 AM 26° Mostly Cloudy 42% 5 mph SE 91%
1 AM 25° Overcast 29% 6 mph SE 94%
2 AM 24° Mostly Cloudy 29% 6 mph SE 94%
3 AM 24° Mostly Cloudy 30% 6 mph SSE 94%
4 AM 24° Mostly Cloudy 30% 7 mph S 93%
5 AM 23° Mostly Cloudy 16% 6 mph S 91%
6 AM 23° Mostly Cloudy 12% 6 mph SSW 90%
7 AM 24° Mostly Cloudy 3% 6 mph SSW 88%
8 AM 26° Partly Cloudy 10% 6 mph SSW 84%
9 AM 28° Partly Cloudy 10% 7 mph SSW 81%
10 AM 29° Partly Cloudy 10% 7 mph SSW 78%
11 AM 30° Partly Cloudy 10% 6 mph SSW 75%
15-Day Forecast
Today
7/26
Partly Cloudy
61%
23°
36°
Mon
7/27
Partly Cloudy
42%
23°
36°
Tue
7/28
Mostly Clear
42%
21°
34°
Wed
7/29
Clear
62%
18°
30°
Thu
7/30
Clear
44%
18°
31°
Fri
7/31
Rain
90%
19°
28°
Sat
8/1
Drizzle
81%
18°
29°
Sun
8/2
Drizzle
60%
19°
29°
Mon
8/3
Drizzle
60%
19°
31°
Tue
8/4
Drizzle
60%
21°
33°
Wed
8/5
Drizzle
60%
21°
33°
Thu
8/6
Drizzle
60%
21°
32°
Fri
8/7
Drizzle
60%
20°
31°
Sat
8/8
Drizzle
60%
19°
32°
Sun
8/9
Drizzle
60%
21°
33°
54
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
54 AQI 10.9 µg/m³
O3
Ground-level ozone
44 AQI 49 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Mon 54 Moderate 44 54
Tue 53 Moderate 36 53
Wed 47 Good 41 47
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 26, 15:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE5280 J/kg
MLCAPE3655 J/kg
MUCAPE5280 J/kg
SBCIN0 J/kg
MLCIN0 J/kg
Lifted Index-9.3
Kinematics
0–6 km Shear22 kt
0–1 km Shear8 kt
Eff. Shear27 kt
0–1 km SRH-20
0–3 km SRH-58
Eff. SRH-58
Storm Motion293° @ 21 kt
0–1 km EHI-0.7
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index36.4
Thermo & Levels
PWAT1.98 in
0–3 km LR6.2 °C/km
700–500 LR6.3 °C/km
Total Totals49.4
LCL935 hPa
LFC996 hPa
EL127 hPa
Freezing Lvl16,604 ft