Prospect Heights, IL Weather & Growing Conditions
This Afternoon
72°F
Slight Chance Rain Showers
A slight chance of rain showers. Mostly cloudy. High near 72, with temperatures falling to around 70 in the afternoon. East wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 72°F | Slight Chance Rain Showers | 10 mph E | 20% |
| Tonight | 62°F | Slight Chance Rain Showers then Showers And Thunderstorms Likely | 10 to 15 mph E | 57% |
| Saturday | 76°F | Showers And Thunderstorms Likely | 10 to 15 mph SE | 91% |
| Saturday Night | 63°F | Showers And Thunderstorms Likely then Showers And Thunderstorms | 5 to 10 mph NE | 80% |
| Sunday | 68°F | Showers And Thunderstorms | 10 to 15 mph NNE | 78% |
| Sunday Night | 56°F | Chance Rain Showers | 15 mph NE | 51% |
| Monday | 65°F | Chance Rain Showers | 15 mph ENE | 44% |
| Monday Night | 53°F | Chance Rain Showers | 10 to 15 mph ENE | 33% |
| Tuesday | 63°F | Slight Chance Rain Showers | 10 to 15 mph NE | 22% |
| Tuesday Night | 53°F | Slight Chance Rain Showers then Mostly Cloudy | 5 to 15 mph NE | 19% |
| Wednesday | 65°F | Partly Sunny | 5 to 10 mph NE | 11% |
| Wednesday Night | 53°F | Mostly Cloudy | 5 to 10 mph NNE | 3% |
| Thursday | 68°F | Partly Sunny | 5 to 10 mph NNE | 6% |
| Thursday Night | 54°F | Mostly Cloudy | 5 mph NNE | 5% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Prospect Heights, IL
Last spring frost
Apr 19
First fall frost
Oct 26
Growing season
190 days
Hardiness zone
6a
Explore more for Prospect Heights, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Chicago Palwaukee Ap, Il (1.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.