Grant Park, IL Weather & Growing Conditions
Overnight
64°F
Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms after 5am. Mostly cloudy. Low around 64, with temperatures rising to around 66 overnight. Southeast wind around 10 mph. Chance of precipitation is 20%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 64°F | Slight Chance Showers And Thunderstorms | 10 mph SE | 19% |
| Saturday | 79°F | Showers And Thunderstorms Likely | 5 to 10 mph SE | 94% |
| Saturday Night | 64°F | Showers And Thunderstorms Likely | 5 mph S | 82% |
| Sunday | 72°F | Showers And Thunderstorms Likely | 5 to 15 mph N | 65% |
| Sunday Night | 54°F | Chance Showers And Thunderstorms | 10 to 15 mph NE | 44% |
| Monday | 65°F | Chance Rain Showers | 15 mph ENE | 54% |
| Monday Night | 50°F | Chance Rain Showers then Mostly Cloudy | 10 to 15 mph NE | 44% |
| Tuesday | 64°F | Slight Chance Rain Showers | 10 to 15 mph NE | 17% |
| Tuesday Night | 50°F | Slight Chance Rain Showers then Mostly Cloudy | 5 to 10 mph NNE | 15% |
| Wednesday | 66°F | Partly Sunny | 5 to 10 mph NNE | 7% |
| Wednesday Night | 51°F | Mostly Cloudy | 5 to 10 mph NNE | 4% |
| Thursday | 68°F | Partly Sunny | 5 to 10 mph NNE | 3% |
| Thursday Night | 52°F | Mostly Cloudy | 5 to 10 mph NNE | 3% |
| Friday | 72°F | Mostly Sunny | 5 to 10 mph NNE | 2% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Grant Park, IL
Last spring frost
Apr 29
First fall frost
Oct 16
Growing season
171 days
Hardiness zone
5b
Explore more for Grant Park, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Lowell, In (11.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.