Flat Rock, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Flat Rock, a village in Crawford County, Illinois.
This Afternoon
77°F
Partly Sunny
Partly sunny, with a high near 77. South wind around 20 mph, with gusts as high as 31 mph.
7-day forecast for Flat Rock
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 77°F | Partly Sunny | 20 mph S | 5% |
| Tonight | 59°F | Rain | 13 to 18 mph S | 95% |
| Wednesday | 67°F | Chance Light Rain then Partly Sunny | 9 to 13 mph SW | 34% |
| Wednesday Night | 45°F | Mostly Cloudy | 3 to 7 mph SW | 0% |
| Thursday | 66°F | Sunny | 6 to 13 mph SW | 0% |
| Thursday Night | 45°F | Partly Cloudy | 5 mph WNW | 4% |
| Friday | 59°F | Partly Sunny | 3 to 10 mph NNW | 4% |
| Friday Night | 42°F | Partly Cloudy | 7 mph NNW | 5% |
| Saturday | 59°F | Mostly Sunny | 7 mph NNW | 0% |
| Saturday Night | 38°F | Partly Cloudy | 3 mph NW | 2% |
| Sunday | 60°F | Mostly Sunny | 3 to 9 mph W | 7% |
| Sunday Night | 37°F | Partly Cloudy | 6 mph WNW | 7% |
| Monday | 60°F | Sunny | 5 to 9 mph W | 5% |
| Monday Night | 37°F | Mostly Clear | 5 mph SW | 2% |
Forecast source: National Weather Service (api.weather.gov) for Flat Rock (38.904, -87.673). Updated through the day.
Growing snapshot for Flat Rock
Last spring frost
Apr 8
First fall frost
Oct 26
Growing season
200 days
Hardiness zone
6b
More local growing data for Flat Rock: nearby ZIP 62427 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Lawrenceville Intl Ap, Il (7.9 mi from Flat Rock). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.