Areal Flood Watch 1:00 PM Flood Watch 9:00 AM Flood Watch 3:00 AM Flood Watch 1:00 PM Flood Watch 3:00 AM

Mercer County, Illinois, United States

Last updated: 9:55 AM CDT  ·  Refresh
21°C
Feels like 23°
Mostly Cloudy
▲ 22°  /  ▼ 14°
Wind
4 mph NW
Humidity
93%
Dew Point
20°
Pressure
29.18 inHg
Visibility
7 mi
UV Index
3.6
Cloud Cover
83%
Sunrise
6:48 AM
Sunset
7:03 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Mercer County is currently mostly cloudy at 21°C. Precipitation is likely — peak probability 79% around 11 AM. Sunrise: 6:48AM · Sunset: 7:03PM.

Alerts

Areal Flood Watch
Expires 1:00 PM
Flood Watch
Expires 9:00 AM
Flood Watch
Expires 3:00 AM
Flood Watch
Expires 1:00 PM
Flood Watch
Expires 3:00 AM
30 AQI · Good Dominant: O3 Air Quality
Hourly Forecast · Next 24 Hours
Now
21°
57%
10 AM
20°
66%
11 AM
19°
79%
12 PM
18°
55%
1 PM
20°
48%
2 PM
20°
32%
3 PM
19°
31%
4 PM
19°
37%
5 PM
19°
37%
6 PM
19°
37%
7 PM
18°
26%
8 PM
18°
27%
9 PM
18°
27%
10 PM
17°
38%
11 PM
17°
38%
12 AM
17°
39%
1 AM
16°
39%
2 AM
16°
42%
3 AM
16°
42%
4 AM
16°
33%
5 AM
16°
37%
6 AM
16°
37%
7 AM
16°
37%
8 AM
16°
45%
7-Day Forecast
Today
22° 14°
Overcast with a 57% chance of rain.
Mon
19° 13°
Overcast with a 54% chance of rain.
Tue
17° 9°
Partly Cloudy with a 55% chance of rain.
Wed
21° 9°
Mostly Clear.
Thu
22° 9°
Clear.
Fri
22° 13°
Clear.
Sat
21° 12°
Clear.
TimeTempConditionsPrecipWindHumidity
Now 21° Mostly Cloudy 57% 4 mph NW 93%
10 AM 20° Mostly Cloudy 66% 6 mph N 92%
11 AM 19° Overcast 79% 10 mph NE 92%
12 PM 18° Overcast 55% 12 mph NE 92%
1 PM 20° Overcast 48% 13 mph NE 91%
2 PM 20° Mostly Cloudy 32% 14 mph NE 91%
3 PM 19° Mostly Cloudy 31% 15 mph NE 90%
4 PM 19° Mostly Cloudy 37% 14 mph NE 89%
5 PM 19° Overcast 37% 14 mph NE 89%
6 PM 19° Overcast 37% 14 mph NE 89%
7 PM 18° Overcast 26% 14 mph ENE 88%
8 PM 18° Overcast 27% 15 mph ENE 88%
9 PM 18° Overcast 27% 15 mph ENE 87%
10 PM 17° Overcast 38% 15 mph NE 87%
11 PM 17° Mostly Cloudy 38% 14 mph NE 87%
12 AM 17° Partly Cloudy 39% 14 mph NE 86%
1 AM 16° Mostly Cloudy 39% 13 mph NE 87%
2 AM 16° Overcast 42% 13 mph NE 87%
3 AM 16° Overcast 42% 12 mph NE 86%
4 AM 16° Overcast 33% 12 mph NE 86%
5 AM 16° Overcast 37% 13 mph ENE 86%
6 AM 16° Overcast 37% 13 mph ENE 86%
7 AM 16° Overcast 37% 13 mph NE 86%
8 AM 16° Overcast 45% 13 mph NE 86%
15-Day Forecast
Today
9/20
Overcast
57%
14°
22°
Mon
9/21
Overcast
54%
13°
19°
Tue
9/22
Partly Cloudy
55%
9°
17°
Wed
9/23
Mostly Clear
16%
9°
21°
Thu
9/24
Clear
3%
9°
22°
Fri
9/25
Clear
8%
13°
22°
Sat
9/26
Clear
17%
12°
21°
Sun
9/27
Drizzle
43%
11°
24°
Mon
9/28
Clear
44%
12°
24°
Tue
9/29
Drizzle
51%
13°
24°
Wed
9/30
Drizzle
60%
14°
24°
Thu
10/1
Drizzle
60%
13°
23°
Fri
10/2
Drizzle
60%
12°
22°
Sat
10/3
Clear
25%
11°
22°
Sun
10/4
Drizzle
60%
10°
21°
30
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
19 AQI 3.6 µg/m³
O3
Ground-level ozone
Dominant
30 AQI 33 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Mon 30 Good 30 19
Tue 20 Good 20 11
Wed 29 Good 29 8
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 Sep 20, 13:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 50 60 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE151 J/kg
MLCAPE20 J/kg
MUCAPE151 J/kg
SBCIN-0 J/kg
MLCIN0 J/kg
Lifted Index-0.2
Kinematics
0–6 km Shear25 kt
0–1 km Shear2 kt
Eff. Shear17 kt
0–1 km SRH-6
0–3 km SRH72
Eff. SRH72
Storm Motion309° @ 21 kt
0–1 km EHI-0.0
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index33.7
Thermo & Levels
PWAT1.96 in
0–3 km LR4.9 °C/km
700–500 LR5.3 °C/km
Total Totals42.7
LCL974 hPa
LFC988 hPa
EL393 hPa
Freezing Lvl13,727 ft