Heat Advisory — Jefferson, IL, Wayne, IL, Edwards, IL, Wabash, 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

Massac County, Illinois, United States

Last updated: 8:06 AM CDT  ·  Refresh
24°C
Feels like 27°
Mostly Clear
▲ 34°  /  ▼ 23°
Wind
8 mph SSW
Humidity
84%
Dew Point
22°
Pressure
29.64 inHg
Visibility
9 mi
UV Index
5.2
Cloud Cover
19%
Sunrise
6:07 AM
Sunset
7:52 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Massac County is currently mostly clear at 25°C. Dry conditions are expected through the next 24 hours. Atmospheric instability is elevated (CAPE up to 3646 J/kg) — isolated convective development possible. Sunrise: 6:07AM · Sunset: 7:52PM.

Alerts

Heat Advisory
Jefferson, IL, Wayne, IL, Edwards, IL, Wabash, 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
44 AQI · Good Dominant: O3 Air Quality
Hourly Forecast · Next 24 Hours
Now
24°
8%
9 AM
26°
14%
10 AM
27°
14%
11 AM
29°
14%
12 PM
30°
7%
1 PM
33°
3%
2 PM
33°
3%
3 PM
33°
3%
4 PM
33°
3%
5 PM
33°
3%
6 PM
32°
3%
7 PM
31°
3%
8 PM
30°
3%
9 PM
27°
3%
10 PM
26°
5%
11 PM
26°
5%
12 AM
26°
5%
1 AM
25°
5%
2 AM
24°
5%
3 AM
24°
5%
4 AM
24°
3%
5 AM
24°
3%
6 AM
24°
3%
7 AM
23°
3%
7-Day Forecast
Today
34° 23°
Mostly Clear.
Tue
35° 23°
Clear.
Wed
37° 24°
Partly Cloudy with a 23% chance of rain.
Thu
36° 24°
Clear with a 58% chance of rain.
Fri
33° 23°
Mostly Clear with a 57% chance of rain.
Sat
37° 23°
Clear.
Sun
38° 24°
Clear.
TimeTempConditionsPrecipWindHumidity
Now 24° Mostly Clear 8% 8 mph SSW 84%
9 AM 26° Clear 14% 10 mph SW 77%
10 AM 27° Clear 14% 10 mph SW 72%
11 AM 29° Clear 14% 11 mph SW 68%
12 PM 30° Clear 7% 11 mph SW 63%
1 PM 33° Partly Cloudy 3% 12 mph SW 59%
2 PM 33° Partly Cloudy 3% 11 mph SW 57%
3 PM 33° Mostly Clear 3% 11 mph SW 56%
4 PM 33° Partly Cloudy 3% 11 mph SSW 56%
5 PM 33° Partly Cloudy 3% 10 mph SSW 60%
6 PM 32° Partly Cloudy 3% 8 mph SSW 67%
7 PM 31° Partly Cloudy 3% 6 mph SSW 72%
8 PM 30° Partly Cloudy 3% 6 mph SSW 74%
9 PM 27° Partly Cloudy 3% 6 mph S 76%
10 PM 26° Mostly Clear 5% 6 mph S 77%
11 PM 26° Mostly Clear 5% 7 mph SSW 78%
12 AM 26° Mostly Clear 5% 7 mph SSW 79%
1 AM 25° Mostly Clear 5% 8 mph SSW 80%
2 AM 24° Mostly Clear 5% 7 mph SSW 82%
3 AM 24° Partly Cloudy 5% 7 mph SSW 83%
4 AM 24° Partly Cloudy 3% 7 mph SSW 85%
5 AM 24° Partly Cloudy 3% 7 mph SSW 85%
6 AM 24° Mostly Clear 3% 7 mph SSW 86%
7 AM 23° Clear 3% 8 mph SSW 86%
15-Day Forecast
Today
8/10
Mostly Clear
14%
23°
34°
Tue
8/11
Clear
6%
23°
35°
Wed
8/12
Partly Cloudy
23%
24°
37°
Thu
8/13
Clear
58%
24°
36°
Fri
8/14
Mostly Clear
57%
23°
33°
Sat
8/15
Clear
15%
23°
37°
Sun
8/16
Clear
15%
24°
38°
Mon
8/17
Drizzle
47%
22°
34°
Tue
8/18
Partly Cloudy
47%
20°
34°
Wed
8/19
Thunderstorm
45%
21°
33°
Thu
8/20
Drizzle
60%
23°
36°
Fri
8/21
Drizzle
60%
22°
34°
Sat
8/22
Drizzle
60%
21°
34°
Sun
8/23
Clear
60%
21°
34°
Mon
8/24
Clear
60%
21°
33°
44
Good
U.S. Air Quality Index · Dominant: O3
50 100 150 200

Air quality is satisfactory and poses little or no health risk.

Pollutant Breakdown · Today
PM2.5
Fine particulate matter
37 AQI 6.6 µg/m³
O3
Ground-level ozone
Dominant
44 AQI 47 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Tue 44 Good 44 37
Wed 42 Good 42 15
Thu 36 Good 36 24
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 Mon Aug 10, 11:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE1356 J/kg
MLCAPE1376 J/kg
MUCAPE1733 J/kg
SBCIN0 J/kg
MLCIN0 J/kg
Lifted Index-6.2
Kinematics
0–6 km Shear8 kt
0–1 km Shear18 kt
Eff. Shear6 kt
0–1 km SRH89
0–3 km SRH109
Eff. SRH109
Storm Motion52° @ 6 kt
0–1 km EHI0.8
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index27.7
Thermo & Levels
PWAT1.62 in
0–3 km LR4.1 °C/km
700–500 LR8.0 °C/km
Total Totals53.2
LCL969 hPa
LFC1004 hPa
EL198 hPa
Freezing Lvl14,780 ft