Mount Prospect, IL Weather & Growing Conditions
Today
86°F
Mostly Sunny
Mostly sunny, with a high near 86. Southwest wind around 10 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 86°F | Mostly Sunny | 10 mph SW | 1% |
| Tonight | 69°F | Mostly Cloudy then Chance Showers And Thunderstorms | 5 mph SSW | 35% |
| Wednesday | 80°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 5 mph WSW | 73% |
| Wednesday Night | 65°F | Showers And Thunderstorms | 0 to 5 mph NW | 88% |
| Thursday | 79°F | Rain Showers Likely then Slight Chance Showers And Thunderstorms | 0 to 5 mph NNE | 63% |
| Thursday Night | 63°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 0 to 5 mph S | 20% |
| Friday | 83°F | Mostly Sunny | 0 to 5 mph SSE | 3% |
| Friday Night | 65°F | Mostly Clear | 0 to 5 mph S | 7% |
| Saturday | 86°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 to 10 mph SW | 15% |
| Saturday Night | 70°F | Slight Chance Showers And Thunderstorms | 5 mph SSW | 21% |
| Sunday | 87°F | Slight Chance Showers And Thunderstorms | 5 to 15 mph SW | 21% |
| Sunday Night | 70°F | Chance Showers And Thunderstorms | 5 to 10 mph SW | 45% |
| Monday | 86°F | Chance Showers And Thunderstorms | 5 to 10 mph SSW | 45% |
| Monday Night | 70°F | Chance Showers And Thunderstorms | 5 to 10 mph WSW | 48% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Mount Prospect, IL
Last spring frost
Apr 19
First fall frost
Oct 26
Growing season
190 days
Hardiness zone
6a
Explore more for Mount Prospect, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Chicago Palwaukee Ap, Il (4.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.