Grayslake, IL Weather & Growing Conditions
Tonight
60°F
Rain
Rain. Cloudy. Low around 60, with temperatures rising to around 62 overnight. South wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 80%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 60°F | Rain | 15 mph S | 78% |
| Wednesday | 63°F | Rain Likely then Rain Showers Likely | 15 mph SSW | 61% |
| Wednesday Night | 47°F | Slight Chance Rain Showers | 15 mph SW | 20% |
| Thursday | 56°F | Chance Rain Showers | 10 to 15 mph WSW | 40% |
| Thursday Night | 41°F | Rain Showers Likely | 5 to 10 mph NW | 57% |
| Friday | 52°F | Chance Rain Showers | 10 to 15 mph N | 26% |
| Friday Night | 34°F | Mostly Cloudy | 0 to 5 mph NNW | 8% |
| Saturday | 52°F | Mostly Sunny | 0 to 5 mph WNW | 6% |
| Saturday Night | 34°F | Partly Cloudy | 0 to 5 mph WSW | 7% |
| Sunday | 57°F | Mostly Sunny then Slight Chance Rain | 5 to 10 mph W | 17% |
| Sunday Night | 35°F | Mostly Clear | 5 mph W | 8% |
| Monday | 60°F | Mostly Sunny | 5 to 10 mph WSW | 3% |
| Monday Night | 39°F | Mostly Clear | 5 mph W | 2% |
| Tuesday | 60°F | Mostly Sunny | 5 to 10 mph WNW | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Grayslake, IL
Last spring frost
Apr 29
First fall frost
Oct 20
Growing season
172 days
Hardiness zone
5b
Explore more for Grayslake, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Mundelein 4 Wsw, Il (5.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.