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

Johnson County, Illinois, United States

Last updated: 12:12 PM CDT  ·  Refresh
32°C
Feels like 40°
Partly Cloudy
▲ 36°  /  ▼ 23°
Wind
4 mph SSW
Humidity
73%
Dew Point
26°
Pressure
29.46 inHg
Visibility
9 mi
UV Index
8.6
Cloud Cover
52%
Sunrise
5:54 AM
Sunset
8:08 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Johnson County is currently partly cloudy at 31°C. Dry conditions are expected through the next 24 hours. Atmospheric instability is elevated (CAPE up to 4488 J/kg) — isolated convective development possible. Sunrise: 5:54AM · Sunset: 8:08PM.

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
43 AQI · Good Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
32°
7%
1 PM
34°
26%
2 PM
34°
31%
3 PM
34°
33%
4 PM
35°
13%
5 PM
36°
24%
6 PM
34°
23%
7 PM
33°
17%
8 PM
32°
27%
9 PM
29°
23%
10 PM
29°
26%
11 PM
28°
18%
12 AM
27°
18%
1 AM
26°
9%
2 AM
26°
9%
3 AM
24°
5%
4 AM
24°
5%
5 AM
23°
5%
6 AM
23°
5%
7 AM
24°
3%
8 AM
26°
10%
9 AM
27°
21%
10 AM
28°
21%
11 AM
31°
24%
7-Day Forecast
Today
36° 23°
Partly Cloudy with a 33% chance of rain.
Mon
36° 23°
Mostly Clear with a 25% chance of rain.
Tue
37° 23°
Mostly Clear with a 49% chance of rain.
Wed
30° 19°
Clear with a 51% chance of rain.
Thu
32° 18°
Clear.
Fri
29° 19°
Drizzle, 60% chance.
Sat
30° 18°
Clear.
TimeTempConditionsPrecipWindHumidity
Now 32° Partly Cloudy 7% 4 mph SSW 73%
1 PM 34° Partly Cloudy 26% 5 mph SW 66%
2 PM 34° Partly Cloudy 31% 6 mph SW 65%
3 PM 34° Partly Cloudy 33% 7 mph SW 64%
4 PM 35° Mostly Clear 13% 8 mph SW 62%
5 PM 36° Partly Cloudy 24% 8 mph SW 65%
6 PM 34° Mostly Clear 23% 7 mph SW 69%
7 PM 33° Mostly Clear 17% 6 mph SSW 74%
8 PM 32° Partly Cloudy 27% 5 mph SSW 79%
9 PM 29° Mostly Cloudy 23% 5 mph SSW 82%
10 PM 29° Mostly Cloudy 26% 4 mph SSW 85%
11 PM 28° Mostly Cloudy 18% 3 mph SSE 87%
12 AM 27° Mostly Cloudy 18% 5 mph ESE 89%
1 AM 26° Partly Cloudy 9% 7 mph E 90%
2 AM 26° Partly Cloudy 9% 6 mph ESE 91%
3 AM 24° Partly Cloudy 5% 5 mph SE 92%
4 AM 24° Partly Cloudy 5% 5 mph SSE 92%
5 AM 23° Partly Cloudy 5% 5 mph S 90%
6 AM 23° Partly Cloudy 5% 5 mph S 90%
7 AM 24° Partly Cloudy 3% 5 mph SSW 89%
8 AM 26° Partly Cloudy 10% 5 mph SSW 84%
9 AM 27° Partly Cloudy 21% 6 mph SSW 80%
10 AM 28° Partly Cloudy 21% 6 mph SSW 77%
11 AM 31° Mostly Clear 24% 6 mph SSW 74%
15-Day Forecast
Today
7/26
Partly Cloudy
33%
23°
36°
Mon
7/27
Mostly Clear
25%
23°
36°
Tue
7/28
Mostly Clear
49%
23°
37°
Wed
7/29
Clear
51%
19°
30°
Thu
7/30
Clear
19%
18°
32°
Fri
7/31
Drizzle
60%
19°
29°
Sat
8/1
Clear
19%
18°
30°
Sun
8/2
Drizzle
60%
19°
31°
Mon
8/3
Drizzle
60%
19°
31°
Tue
8/4
Drizzle
60%
21°
33°
Wed
8/5
Drizzle
60%
22°
33°
Thu
8/6
Drizzle
60%
21°
32°
Fri
8/7
Drizzle
60%
21°
32°
Sat
8/8
Drizzle
60%
20°
33°
Sun
8/9
Drizzle
60%
21°
33°
43
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
43 AQI 7.9 µg/m³
O3
Ground-level ozone
31 AQI 34 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Mon 43 Good 31 43
Tue 53 Moderate 33 53
Wed 41 Good 41 33
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
SBCAPE5154 J/kg
MLCAPE3190 J/kg
MUCAPE5154 J/kg
SBCIN0 J/kg
MLCIN0 J/kg
Lifted Index-8.3
Kinematics
0–6 km Shear22 kt
0–1 km Shear8 kt
Eff. Shear26 kt
0–1 km SRH-21
0–3 km SRH-55
Eff. SRH-55
Storm Motion295° @ 19 kt
0–1 km EHI-0.7
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index34.8
Thermo & Levels
PWAT1.88 in
0–3 km LR6.6 °C/km
700–500 LR5.6 °C/km
Total Totals46.4
LCL928 hPa
LFC998 hPa
EL124 hPa
Freezing Lvl16,906 ft