Grafton, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Grafton, a city in Jersey County, Illinois.
This Afternoon
73°F
Light Rain
Rain and a slight chance of thunderstorms. Cloudy. High near 73, with temperatures falling to around 66 in the afternoon. South wind around 21 mph, with gusts as high as 32 mph. Chance of precipitation is 100%.
7-day forecast for Grafton
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 73°F | Light Rain | 21 mph S | 99% |
| Tonight | 54°F | Light Rain | 12 to 18 mph SW | 86% |
| Wednesday | 62°F | Chance Rain Showers then Mostly Cloudy | 10 to 16 mph W | 12% |
| Wednesday Night | 45°F | Partly Cloudy | 9 mph SW | 0% |
| Thursday | 64°F | Sunny | 7 to 14 mph W | 4% |
| Thursday Night | 45°F | Mostly Cloudy | 7 mph NW | 14% |
| Friday | 57°F | Mostly Cloudy | 7 to 12 mph NW | 5% |
| Friday Night | 40°F | Mostly Cloudy | 2 to 8 mph N | 1% |
| Saturday | 56°F | Mostly Sunny | 5 mph NW | 0% |
| Saturday Night | 38°F | Partly Cloudy | 3 mph W | 1% |
| Sunday | 62°F | Sunny | 3 to 8 mph W | 8% |
| Sunday Night | 38°F | Mostly Clear | 6 mph W | 4% |
| Monday | 66°F | Sunny | 3 to 9 mph SW | 2% |
| Monday Night | 43°F | Mostly Clear | 6 mph SW | 1% |
Forecast source: National Weather Service (api.weather.gov) for Grafton (38.976, -90.426). Updated through the day.
Growing snapshot for Grafton
Last spring frost
Apr 5
First fall frost
Oct 27
Growing season
203 days
Hardiness zone
6b
More local growing data for Grafton: nearby ZIP 62037 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, St Charles Co Ap, Mo (6 mi from Grafton). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.