Severe Thunderstorm Watch 12:00 AM

Mercer County, Illinois, United States

Last updated: 10:10 PM CDT  ·  Refresh
22°C
Feels like 25°
Mostly Clear
▲ 29°  /  ▼ 16°
Wind
6 mph NW
Humidity
92%
Dew Point
22°
Pressure
29.23 inHg
Visibility
8 mi
UV Index
0.0
Cloud Cover
26%
Sunrise
6:18 AM
Sunset
7:52 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Mercer County is currently mostly clear at 22°C. Dry conditions are expected through the next 24 hours. Atmospheric instability is elevated (CAPE up to 1872 J/kg) — isolated convective development possible. Sunrise: 6:18AM · Sunset: 7:52PM.

Alerts

Severe Thunderstorm Watch
Expires 12:00 AM
31 AQI · Good Dominant: O3 Air Quality
Hourly Forecast · Next 24 Hours
Now
22°
3%
11 PM
22°
14%
12 AM
21°
14%
1 AM
19°
3%
2 AM
19°
3%
3 AM
18°
3%
4 AM
18°
3%
5 AM
17°
3%
6 AM
17°
3%
7 AM
17°
3%
8 AM
18°
3%
9 AM
21°
5%
10 AM
23°
5%
11 AM
24°
5%
12 PM
26°
5%
1 PM
28°
5%
2 PM
28°
5%
3 PM
28°
5%
4 PM
28°
5%
5 PM
28°
5%
6 PM
27°
3%
7 PM
26°
3%
8 PM
25°
3%
9 PM
22°
3%
7-Day Forecast
Tonight
29° 16°
Mostly Clear.
Sat
28° 16°
Clear.
Sun
27° 13°
Clear.
Mon
24° 14°
Overcast with a 54% chance of rain.
Tue
27° 14°
Rain, 64% chance.
Wed
29° 18°
Thunderstorm, 64% chance.
Thu
29° 17°
Clear.
TimeTempConditionsPrecipWindHumidity
Now 22° Mostly Clear 3% 6 mph NW 92%
11 PM 22° Clear 14% 7 mph NNW 88%
12 AM 21° Clear 14% 6 mph NNW 89%
1 AM 19° Clear 3% 6 mph NW 89%
2 AM 19° Clear 3% 6 mph NNW 90%
3 AM 18° Clear 3% 6 mph NNW 90%
4 AM 18° Clear 3% 6 mph NNW 90%
5 AM 17° Clear 3% 5 mph NNW 91%
6 AM 17° Mostly Clear 3% 5 mph NW 91%
7 AM 17° Mostly Clear 3% 5 mph NW 90%
8 AM 18° Mostly Clear 3% 6 mph NW 85%
9 AM 21° Clear 5% 6 mph WNW 80%
10 AM 23° Clear 5% 8 mph WNW 75%
11 AM 24° Clear 5% 9 mph WNW 70%
12 PM 26° Clear 5% 11 mph WNW 65%
1 PM 28° Clear 5% 12 mph NW 62%
2 PM 28° Clear 5% 12 mph NW 61%
3 PM 28° Clear 5% 12 mph NW 61%
4 PM 28° Clear 5% 12 mph NW 61%
5 PM 28° Clear 5% 11 mph NW 64%
6 PM 27° Clear 3% 10 mph NW 69%
7 PM 26° Clear 3% 10 mph NW 71%
8 PM 25° Clear 3% 10 mph NW 72%
9 PM 22° Clear 3% 8 mph NW 74%
15-Day Forecast
Today
8/21
Mostly Clear
3%
16°
29°
Sat
8/22
Clear
5%
16°
28°
Sun
8/23
Clear
3%
13°
27°
Mon
8/24
Overcast
54%
14°
24°
Tue
8/25
Rain
64%
14°
27°
Wed
8/26
Thunderstorm
64%
18°
29°
Thu
8/27
Clear
8%
17°
29°
Fri
8/28
Clear
31%
17°
27°
Sat
8/29
Thunderstorm
68%
17°
31°
Sun
8/30
Drizzle
44%
19°
32°
Mon
8/31
Drizzle
60%
19°
32°
Tue
9/1
Drizzle
60%
20°
31°
Wed
9/2
Drizzle
60%
19°
30°
Thu
9/3
Drizzle
60%
18°
29°
Fri
9/4
Clear
60%
18°
30°
31
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
27 AQI 4.8 µg/m³
O3
Ground-level ozone
Dominant
31 AQI 35 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Today 31 Good 31 27
Sun 36 Good 36 28
Mon 31 Good 31 7
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 Sat Aug 22, 01:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 50 60 70 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE1989 J/kg
MLCAPE2533 J/kg
MUCAPE3360 J/kg
SBCIN-139 J/kg
MLCIN-41 J/kg
Lifted Index-5.7
Kinematics
0–6 km Shear23 kt
0–1 km Shear19 kt
Eff. Shear23 kt
0–1 km SRH92
0–3 km SRH132
Eff. SRH132
Storm Motion338° @ 29 kt
0–1 km EHI1.1
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell5.2
K-Index24.1
Thermo & Levels
PWAT1.38 in
0–3 km LR5.0 °C/km
700–500 LR6.9 °C/km
Total Totals51.4
LCL975 hPa
LFC824 hPa
EL216 hPa
Freezing Lvl13,084 ft