Excessive Heat Watch 7:00 PM

Saint Clair County, Illinois, United States

Last updated: 8:57 AM CDT  ·  Refresh
27°C
Feels like 31°
Mostly Cloudy
▲ 37°  /  ▼ 23°
Wind
2 mph WSW
Humidity
86%
Dew Point
25°
Pressure
29.41 inHg
Visibility
4 mi
UV Index
3.9
Cloud Cover
82%
Sunrise
5:56 AM
Sunset
8:15 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Saint Clair County is currently mostly cloudy at 27°C. Precipitation is likely — peak probability 67% around 6 PM. Atmospheric instability is elevated (CAPE up to 4022 J/kg) — isolated convective development possible. Sunrise: 5:56AM · Sunset: 8:15PM.

Alerts

Excessive Heat Watch
Expires 7:00 PM
54 AQI · Moderate Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
27°
18%
9 AM
29°
27%
10 AM
31°
27%
11 AM
32°
37%
12 PM
33°
36%
1 PM
36°
44%
2 PM
36°
52%
3 PM
37°
53%
4 PM
35°
61%
5 PM
34°
55%
6 PM
32°
67%
7 PM
30°
59%
8 PM
29°
62%
9 PM
27°
47%
10 PM
27°
23%
11 PM
26°
10%
12 AM
26°
3%
1 AM
26°
3%
2 AM
25°
3%
3 AM
24°
3%
4 AM
24°
3%
5 AM
23°
3%
6 AM
24°
3%
7 AM
24°
9%
7-Day Forecast
Today
37° 23°
Partly Cloudy with a 62% chance of rain.
Mon
37° 23°
Partly Cloudy with a 36% chance of rain.
Tue
36° 21°
Mostly Clear with a 25% chance of rain.
Wed
31° 18°
Mostly Clear with a 37% chance of rain.
Thu
31° 18°
Clear.
Fri
27° 19°
Rain, 71% chance.
Sat
30° 18°
Rain, 63% chance.
TimeTempConditionsPrecipWindHumidity
Now 27° Mostly Cloudy 18% 2 mph WSW 86%
9 AM 29° Partly Cloudy 27% 4 mph WSW 78%
10 AM 31° Partly Cloudy 27% 4 mph SW 73%
11 AM 32° Mostly Cloudy 37% 5 mph WSW 67%
12 PM 33° Mostly Cloudy 36% 6 mph WSW 62%
1 PM 36° Mostly Cloudy 44% 5 mph WSW 58%
2 PM 36° Partly Cloudy 52% 6 mph WSW 55%
3 PM 37° Mostly Clear 53% 6 mph WSW 51%
4 PM 35° Partly Cloudy 61% 5 mph SW 59%
5 PM 34° Partly Cloudy 55% 7 mph SSW 68%
6 PM 32° Mostly Cloudy 67% 10 mph S 78%
7 PM 30° Thunderstorm 59% 7 mph SSE 78%
8 PM 29° Mostly Cloudy 62% 6 mph E 78%
9 PM 27° Mostly Cloudy 47% 8 mph ESE 76%
10 PM 27° Partly Cloudy 23% 5 mph SSW 78%
11 PM 26° Partly Cloudy 10% 5 mph SSW 80%
12 AM 26° Partly Cloudy 3% 6 mph SW 82%
1 AM 26° Partly Cloudy 3% 6 mph SSW 85%
2 AM 25° Partly Cloudy 3% 6 mph SSW 88%
3 AM 24° Mostly Cloudy 3% 6 mph S 90%
4 AM 24° Mostly Cloudy 3% 6 mph S 90%
5 AM 23° Mostly Cloudy 3% 6 mph SSE 90%
6 AM 24° Mostly Cloudy 3% 7 mph SE 90%
7 AM 24° Mostly Cloudy 9% 6 mph SSE 86%
15-Day Forecast
Today
7/26
Partly Cloudy
62%
23°
37°
Mon
7/27
Partly Cloudy
36%
23°
37°
Tue
7/28
Mostly Clear
25%
21°
36°
Wed
7/29
Mostly Clear
37%
18°
31°
Thu
7/30
Clear
16%
18°
31°
Fri
7/31
Rain
71%
19°
27°
Sat
8/1
Rain
63%
18°
30°
Sun
8/2
Drizzle
42%
19°
30°
Mon
8/3
Drizzle
44%
19°
32°
Tue
8/4
Drizzle
51%
21°
34°
Wed
8/5
Drizzle
60%
21°
34°
Thu
8/6
Drizzle
60%
20°
32°
Fri
8/7
Drizzle
60%
20°
31°
Sat
8/8
Drizzle
60%
20°
33°
Sun
8/9
Drizzle
60%
21°
33°
54
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
54 AQI 10.7 µg/m³
O3
Ground-level ozone
47 AQI 51 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Mon 54 Moderate 47 54
Tue 52 Moderate 40 52
Wed 44 Good 44 42
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, 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
SBCAPE2757 J/kg
MLCAPE2550 J/kg
MUCAPE2945 J/kg
SBCIN-110 J/kg
MLCIN0 J/kg
Lifted Index-5.2
Kinematics
0–6 km Shear12 kt
0–1 km Shear13 kt
Eff. Shear23 kt
0–1 km SRH-15
0–3 km SRH-30
Eff. SRH-30
Storm Motion299° @ 21 kt
0–1 km EHI-0.3
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index32.6
Thermo & Levels
PWAT1.82 in
0–3 km LR5.1 °C/km
700–500 LR5.8 °C/km
Total Totals46.9
LCL960 hPa
LFC743 hPa
EL158 hPa
Freezing Lvl16,742 ft