Crystal Lake, IL Weather & Growing Conditions
Today
84°F
Mostly Sunny
Mostly sunny, with a high near 84. Southwest wind 5 to 10 mph, with gusts as high as 20 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 84°F | Mostly Sunny | 5 to 10 mph SW | 0% |
| Tonight | 67°F | Mostly Cloudy then Slight Chance Showers And Thunderstorms | 0 to 5 mph SW | 54% |
| Wednesday | 78°F | Showers And Thunderstorms Likely | 0 to 5 mph WSW | 74% |
| Wednesday Night | 62°F | Showers And Thunderstorms | 0 to 5 mph NW | 80% |
| Thursday | 78°F | Chance Rain Showers then Slight Chance Showers And Thunderstorms | 0 to 5 mph NE | 53% |
| Thursday Night | 60°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 0 to 5 mph ENE | 15% |
| Friday | 81°F | Mostly Sunny | 0 to 5 mph S | 4% |
| Friday Night | 63°F | Mostly Clear | 0 to 5 mph SSW | 8% |
| Saturday | 83°F | Mostly Sunny | 5 mph SW | 11% |
| Saturday Night | 68°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 5 mph SSW | 20% |
| Sunday | 84°F | Slight Chance Showers And Thunderstorms | 5 to 10 mph SW | 20% |
| Sunday Night | 68°F | Chance Showers And Thunderstorms | 5 to 10 mph SW | 45% |
| Monday | 83°F | Chance Showers And Thunderstorms | 5 mph SSW | 45% |
| Monday Night | 68°F | Chance Showers And Thunderstorms | 5 mph W | 45% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Crystal Lake, IL
Last spring frost
Apr 25
First fall frost
Oct 22
Growing season
179 days
Hardiness zone
5b
Explore more for Crystal Lake, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Crystal Lake 4Nw, Il (4 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.