Flat Rock, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Flat Rock, a village in Crawford County, Illinois.
Tonight
70°F
Partly Cloudy
Partly cloudy, with a low around 70. East southeast wind 3 to 8 mph.
7-day forecast for Flat Rock
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 70°F | Partly Cloudy | 3 to 8 mph ESE | 10% |
| Saturday | 95°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 to 9 mph SSW | 17% |
| Saturday Night | 72°F | Partly Cloudy | 7 mph S | 8% |
| Sunday | 94°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 to 9 mph W | 19% |
| Sunday Night | 66°F | Chance Showers And Thunderstorms | 9 mph NNE | 36% |
| Monday | 82°F | Showers And Thunderstorms Likely | 9 to 13 mph NE | 55% |
| Monday Night | 60°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 9 to 14 mph NNE | 55% |
| Tuesday | 75°F | Chance Showers And Thunderstorms | 10 to 14 mph NNE | 40% |
| Tuesday Night | 56°F | Mostly Cloudy | 7 to 14 mph NNE | 11% |
| Wednesday | 74°F | Partly Sunny | 8 to 12 mph NNE | 5% |
| Wednesday Night | 56°F | Mostly Cloudy | 5 to 12 mph NNE | 5% |
| Thursday | 75°F | Mostly Sunny | 6 to 10 mph N | 4% |
| Thursday Night | 57°F | Partly Cloudy | 5 to 10 mph NNE | 4% |
| Friday | 76°F | Mostly Sunny | 6 to 10 mph NNE | 3% |
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 Sep 19, 2026.