McHenry, IL Weather & Growing Conditions
This Afternoon
69°F
Rain Showers Likely
Rain showers likely. Mostly cloudy. High near 69, with temperatures falling to around 65 in the afternoon. South wind around 15 mph, with gusts as high as 30 mph. Chance of precipitation is 70%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 69°F | Rain Showers Likely | 15 mph S | 67% |
| Tonight | 59°F | Rain Showers | 15 mph S | 80% |
| Wednesday | 62°F | Rain Showers Likely | 15 mph SSW | 58% |
| Wednesday Night | 47°F | Chance Rain Showers | 15 mph SW | 25% |
| Thursday | 56°F | Chance Rain Showers | 10 to 15 mph WSW | 49% |
| Thursday Night | 41°F | Chance Rain Showers | 5 to 10 mph NW | 51% |
| Friday | 51°F | Slight Chance Rain Showers | 10 to 15 mph N | 23% |
| Friday Night | 34°F | Mostly Cloudy | 0 to 5 mph NNW | 4% |
| Saturday | 52°F | Mostly Sunny | 0 to 5 mph WNW | 5% |
| Saturday Night | 34°F | Partly Cloudy | 0 mph | 7% |
| Sunday | 57°F | Mostly Sunny then Slight Chance Rain | 0 to 5 mph W | 18% |
| Sunday Night | 35°F | Mostly Clear | 0 to 5 mph W | 8% |
| Monday | 60°F | Mostly Sunny | 0 to 10 mph WSW | 3% |
| Monday Night | 39°F | Mostly Clear | 5 mph W | 2% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for McHenry, IL
Last spring frost
May 1
First fall frost
Oct 11
Growing season
162 days
Hardiness zone
5b
Explore more for McHenry, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Mc Henry -Wg Stratton L&D, Il (2.5 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.