Excessive Heat Watch 7:00 PM

Saint Charles County, Missouri, United States

Last updated: 7:44 AM CDT  ·  Refresh
27°C
Feels like 30°
Partly Cloudy
▲ 38°  /  ▼ 26°
Wind
3 mph WSW
Humidity
90%
Dew Point
25°
Pressure
29.37 inHg
Visibility
4 mi
UV Index
4.1
Cloud Cover
56%
Sunrise
5:58 AM
Sunset
8:19 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Saint Charles County is currently partly cloudy at 27°C. Dry conditions are expected through the next 24 hours. Atmospheric instability is elevated (CAPE up to 4216 J/kg) — isolated convective development possible. Sunrise: 5:58AM · Sunset: 8:19PM.

Alerts

Excessive Heat Watch
Expires 7:00 PM
55 AQI · Moderate Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
27°
11%
8 AM
28°
29%
9 AM
31°
21%
10 AM
32°
21%
11 AM
33°
21%
12 PM
35°
21%
1 PM
37°
35%
2 PM
38°
35%
3 PM
38°
35%
4 PM
37°
36%
5 PM
37°
29%
6 PM
35°
24%
7 PM
33°
16%
8 PM
32°
17%
9 PM
30°
17%
10 PM
29°
17%
11 PM
29°
8%
12 AM
28°
3%
1 AM
27°
3%
2 AM
27°
3%
3 AM
27°
3%
4 AM
27°
3%
5 AM
27°
3%
6 AM
26°
3%
7-Day Forecast
Today
38° 26°
Partly Cloudy with a 36% chance of rain.
Mon
39° 26°
Partly Cloudy with a 30% chance of rain.
Tue
37° 23°
Mostly Clear with a 51% chance of rain.
Wed
33° 21°
Mostly Cloudy.
Thu
34° 20°
Rain, 29% chance.
Fri
32° 21°
Rain, 82% chance.
Sat
33° 19°
Clear with a 52% chance of rain.
TimeTempConditionsPrecipWindHumidity
Now 27° Partly Cloudy 11% 3 mph WSW 90%
8 AM 28° Partly Cloudy 29% 4 mph WSW 82%
9 AM 31° Mostly Clear 21% 5 mph WSW 74%
10 AM 32° Mostly Clear 21% 6 mph W 68%
11 AM 33° Partly Cloudy 21% 6 mph W 62%
12 PM 35° Partly Cloudy 21% 6 mph W 56%
1 PM 37° Mostly Cloudy 35% 6 mph W 53%
2 PM 38° Partly Cloudy 35% 7 mph W 51%
3 PM 38° Partly Cloudy 35% 7 mph W 48%
4 PM 37° Partly Cloudy 36% 7 mph W 52%
5 PM 37° Mostly Cloudy 29% 7 mph WSW 56%
6 PM 35° Mostly Cloudy 24% 7 mph SSW 62%
7 PM 33° Partly Cloudy 16% 6 mph S 65%
8 PM 32° Mostly Clear 17% 7 mph SSE 66%
9 PM 30° Clear 17% 8 mph SE 67%
10 PM 29° Clear 17% 7 mph SSE 69%
11 PM 29° Mostly Clear 8% 6 mph S 72%
12 AM 28° Mostly Clear 3% 6 mph SSW 74%
1 AM 27° Mostly Clear 3% 6 mph SSW 74%
2 AM 27° Mostly Clear 3% 6 mph SSW 74%
3 AM 27° Mostly Clear 3% 7 mph SSW 74%
4 AM 27° Partly Cloudy 3% 6 mph SSW 74%
5 AM 27° Partly Cloudy 3% 5 mph SSW 76%
6 AM 26° Partly Cloudy 3% 6 mph S 76%
15-Day Forecast
Today
7/26
Partly Cloudy
36%
26°
38°
Mon
7/27
Partly Cloudy
30%
26°
39°
Tue
7/28
Mostly Clear
51%
23°
37°
Wed
7/29
Mostly Cloudy
17%
21°
33°
Thu
7/30
Rain
29%
20°
34°
Fri
7/31
Rain
82%
21°
32°
Sat
8/1
Clear
52%
19°
33°
Sun
8/2
Drizzle
42%
20°
33°
Mon
8/3
Drizzle
44%
20°
34°
Tue
8/4
Drizzle
51%
22°
36°
Wed
8/5
Drizzle
60%
22°
36°
Thu
8/6
Drizzle
60%
21°
35°
Fri
8/7
Drizzle
60%
21°
34°
Sat
8/8
Drizzle
60%
21°
36°
Sun
8/9
Drizzle
60%
22°
37°
55
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
55 AQI 11.3 µg/m³
O3
Ground-level ozone
36 AQI 40 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Mon 55 Moderate 36 55
Tue 44 Good 37 44
Wed 45 Good 45 35
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
SBCAPE2721 J/kg
MLCAPE2506 J/kg
MUCAPE2721 J/kg
SBCIN-155 J/kg
MLCIN0 J/kg
Lifted Index-5.1
Kinematics
0–6 km Shear12 kt
0–1 km Shear15 kt
Eff. Shear21 kt
0–1 km SRH-8
0–3 km SRH-16
Eff. SRH-16
Storm Motion296° @ 21 kt
0–1 km EHI-0.1
Composite Parameters
Sig. Tornado0.0
STP (eff)0.0
Supercell0.0
K-Index32.3
Thermo & Levels
PWAT1.78 in
0–3 km LR4.8 °C/km
700–500 LR5.9 °C/km
Total Totals47.2
LCL972 hPa
LFC731 hPa
EL161 hPa
Freezing Lvl16,785 ft