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: 1:30 PM CDT  ·  Refresh
33°C
Feels like 44°
Mostly Clear
▲ 36°  /  ▼ 22°
Wind
5 mph SW
Humidity
72%
Dew Point
27°
Pressure
29.41 inHg
Visibility
10 mi
UV Index
9.4
Cloud Cover
29%
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 mostly clear at 33°C. Precipitation is likely — peak probability 71% around 10 PM. Atmospheric instability is elevated (CAPE up to 4493 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
55 AQI · Moderate Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
33°
23%
2 PM
34°
44%
3 PM
35°
44%
4 PM
35°
43%
5 PM
36°
42%
6 PM
35°
42%
7 PM
34°
47%
8 PM
33°
60%
9 PM
30°
61%
10 PM
29°
71%
11 PM
27°
64%
12 AM
26°
54%
1 AM
24°
36%
2 AM
24°
45%
3 AM
23°
32%
4 AM
23°
33%
5 AM
22°
12%
6 AM
23°
12%
7 AM
23°
3%
8 AM
25°
9%
9 AM
28°
10%
10 AM
29°
10%
11 AM
30°
10%
12 PM
31°
10%
7-Day Forecast
Today
36° 22°
Mostly Clear with a 71% chance of rain.
Mon
36° 22°
Partly Cloudy with a 36% 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.
Fri
29° 19°
Rain, 81% chance.
Sat
29° 18°
Drizzle, 81% chance.
TimeTempConditionsPrecipWindHumidity
Now 33° Mostly Clear 23% 5 mph SW 72%
2 PM 34° Partly Cloudy 44% 8 mph WSW 70%
3 PM 35° Mostly Clear 44% 8 mph WSW 67%
4 PM 35° Mostly Clear 43% 8 mph WSW 66%
5 PM 36° Mostly Clear 42% 7 mph WSW 68%
6 PM 35° Mostly Clear 42% 5 mph WSW 71%
7 PM 34° Partly Cloudy 47% 4 mph SW 74%
8 PM 33° Partly Cloudy 60% 4 mph SSW 78%
9 PM 30° Partly Cloudy 61% 5 mph SSW 81%
10 PM 29° Mostly Cloudy 71% 4 mph SW 84%
11 PM 27° Rain 64% 5 mph ESE 88%
12 AM 26° Overcast 54% 6 mph ESE 93%
1 AM 24° Mostly Cloudy 36% 7 mph SE 95%
2 AM 24° Mostly Cloudy 45% 6 mph SSE 94%
3 AM 23° Mostly Cloudy 32% 7 mph SSE 94%
4 AM 23° Mostly Cloudy 33% 7 mph SSE 93%
5 AM 22° Partly Cloudy 12% 7 mph SSE 91%
6 AM 23° Partly Cloudy 12% 7 mph S 89%
7 AM 23° Partly Cloudy 3% 7 mph S 87%
8 AM 25° Partly Cloudy 9% 8 mph S 83%
9 AM 28° Mostly Clear 10% 8 mph S 80%
10 AM 29° Mostly Clear 10% 8 mph S 77%
11 AM 30° Partly Cloudy 10% 7 mph S 74%
12 PM 31° Partly Cloudy 10% 7 mph S 70%
15-Day Forecast
Today
7/26
Mostly Clear
71%
22°
36°
Mon
7/27
Partly Cloudy
36%
22°
36°
Tue
7/28
Mostly Clear
42%
21°
34°
Wed
7/29
Clear
62%
18°
30°
Thu
7/30
Clear
19%
18°
31°
Fri
7/31
Rain
81%
19°
29°
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%
20°
32°
Fri
8/7
Drizzle
60%
20°
31°
Sat
8/8
Drizzle
60%
19°
32°
Sun
8/9
Drizzle
60%
21°
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 11.2 µg/m³
O3
Ground-level ozone
45 AQI 50 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Mon 55 Moderate 45 55
Tue 55 Moderate 42 55
Wed 44 Good 41 44
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, 17:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 50 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE5956 J/kg
MLCAPE4454 J/kg
MUCAPE5956 J/kg
SBCIN0 J/kg
MLCIN0 J/kg
Lifted Index-10.8
Kinematics
0–6 km Shear29 kt
0–1 km Shear7 kt
Eff. Shear33 kt
0–1 km SRH-11
0–3 km SRH-45
Eff. SRH-45
Storm Motion278° @ 21 kt
0–1 km EHI-0.4
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index39.0
Thermo & Levels
PWAT2.27 in
0–3 km LR6.8 °C/km
700–500 LR6.6 °C/km
Total Totals51.7
LCL911 hPa
LFC996 hPa
EL124 hPa
Freezing Lvl16,004 ft