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Mount Prospect, IL Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Mount Prospect, a village in Cook County, Illinois.

This Afternoon
71°F
Chance Rain
A chance of rain before 3pm, then a chance of rain and a slight chance of thunderstorms. Mostly cloudy. High near 71, with temperatures falling to around 69 in the afternoon. South wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.

7-day forecast for Mount Prospect

WhenTempForecastWindPrecip
This Afternoon 71°F Chance Rain 15 to 20 mph S 41%
Tonight 61°F Rain 15 mph S 81%
Wednesday 64°F Rain Likely 15 mph SSW 58%
Wednesday Night 48°F Slight Chance Rain then Mostly Cloudy 15 mph SW 18%
Thursday 57°F Chance Rain 10 to 15 mph WSW 31%
Thursday Night 43°F Chance Rain 5 to 10 mph WNW 53%
Friday 52°F Chance Rain 10 to 15 mph N 33%
Friday Night 38°F Mostly Cloudy 5 to 10 mph NNW 11%
Saturday 52°F Mostly Sunny 5 mph WNW 8%
Saturday Night 37°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 38°F Mostly Clear 5 mph WNW 9%
Monday 60°F Sunny 5 to 10 mph WSW 4%
Monday Night 42°F Partly Cloudy 5 to 10 mph W 2%

Forecast source: National Weather Service (api.weather.gov) for Mount Prospect (42.064, -87.937). Updated through the day.

Growing snapshot for Mount Prospect

Last spring frost
Apr 19
First fall frost
Oct 26
Growing season
190 days
Hardiness zone
6a

More local growing data for Mount Prospect: nearby ZIP 60056 weather · frost dates · planting calendar · Illinois frost dates

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Climate data from the nearest NOAA station, Chicago Palwaukee Ap, Il (4.1 mi from Mount Prospect). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.