McHenry County, Illinois, United States

Last updated: 11:22 PM CDT  ·  Refresh
23°C
Feels like 25°
Mostly Clear
▲ 27°  /  ▼ 19°
Wind
5 mph WNW
Humidity
87%
Dew Point
21°
Pressure
28.72 inHg
Visibility
10 mi
UV Index
0.0
Cloud Cover
12%
Sunrise
5:41 AM
Sunset
8:18 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: McHenry County is currently mostly clear at 23°C. Dry conditions are expected through the next 24 hours. Atmospheric instability is elevated (CAPE up to 1039 J/kg) — isolated convective development possible. Sunrise: 5:41AM · Sunset: 8:18PM.

Alerts

No active alerts for this location.
49 AQI · Good Dominant: PM2.5 Air Quality
Hourly Forecast · Next 24 Hours
Now
23°
4%
12 AM
22°
16%
1 AM
22°
3%
2 AM
22°
3%
3 AM
22°
3%
4 AM
21°
3%
5 AM
19°
3%
6 AM
19°
6%
7 AM
19°
6%
8 AM
20°
6%
9 AM
22°
6%
10 AM
23°
7%
11 AM
24°
7%
12 PM
26°
7%
1 PM
24°
7%
2 PM
24°
7%
3 PM
24°
7%
4 PM
24°
7%
5 PM
24°
7%
6 PM
24°
3%
7 PM
23°
3%
8 PM
22°
3%
9 PM
21°
3%
10 PM
19°
3%
7-Day Forecast
Tonight
27° 19°
Mostly Clear.
Tue
26° 16°
Mostly Clear.
Wed
29° 16°
Clear.
Thu
29° 19°
Partly Cloudy.
Fri
23° 18°
Drizzle, 69% chance.
Sat
29° 17°
Drizzle, 76% chance.
Sun
27° 16°
Clear.
TimeTempConditionsPrecipWindHumidity
Now 23° Mostly Clear 4% 5 mph WNW 87%
12 AM 22° Clear 16% 6 mph NNW 86%
1 AM 22° Clear 3% 8 mph N 87%
2 AM 22° Mostly Clear 3% 10 mph N 89%
3 AM 22° Partly Cloudy 3% 12 mph NNE 90%
4 AM 21° Mostly Cloudy 3% 12 mph NNE 91%
5 AM 19° Mostly Cloudy 3% 11 mph NNE 91%
6 AM 19° Mostly Cloudy 6% 10 mph NNE 91%
7 AM 19° Mostly Cloudy 6% 10 mph N 89%
8 AM 20° Mostly Cloudy 6% 10 mph N 83%
9 AM 22° Mostly Cloudy 6% 10 mph NNE 77%
10 AM 23° Partly Cloudy 7% 11 mph NNE 71%
11 AM 24° Partly Cloudy 7% 11 mph NNE 66%
12 PM 26° Mostly Clear 7% 11 mph NNE 60%
1 PM 24° Clear 7% 11 mph NNE 56%
2 PM 24° Clear 7% 11 mph NNE 53%
3 PM 24° Clear 7% 11 mph NNE 51%
4 PM 24° Clear 7% 11 mph NNE 50%
5 PM 24° Clear 7% 10 mph NNE 53%
6 PM 24° Clear 3% 10 mph NE 55%
7 PM 23° Clear 3% 9 mph NE 58%
8 PM 22° Clear 3% 9 mph NE 62%
9 PM 21° Clear 3% 8 mph NE 65%
10 PM 19° Clear 3% 8 mph NE 67%
15-Day Forecast
Today
7/27
Mostly Clear
4%
19°
27°
Tue
7/28
Mostly Clear
7%
16°
26°
Wed
7/29
Clear
12%
16°
29°
Thu
7/30
Partly Cloudy
14%
19°
29°
Fri
7/31
Drizzle
69%
18°
23°
Sat
8/1
Drizzle
76%
17°
29°
Sun
8/2
Clear
8%
16°
27°
Mon
8/3
Clear
17%
16°
28°
Tue
8/4
Drizzle
44%
18°
29°
Wed
8/5
Rain
68%
19°
31°
Thu
8/6
Rain
64%
17°
28°
Fri
8/7
Drizzle
60%
16°
28°
Sat
8/8
Drizzle
60%
17°
28°
Sun
8/9
Drizzle
60%
18°
28°
Mon
8/10
Drizzle
60%
18°
28°
49
Good
U.S. Air Quality Index · Dominant: PM2.5
50 100 150 200

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

Pollutant Breakdown · Today
PM2.5
Fine particulate matter
Dominant
49 AQI 8.9 µg/m³
O3
Ground-level ozone
42 AQI 45 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Today 49 Good 42 49
Wed 35 Good 35 27
Thu 39 Good 39 38
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.

Model sounding data is unavailable for this location.