Grafton, IL Weather & Growing Conditions
Today
88°F
Sunny
Sunny, with a high near 88. South wind around 5 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 88°F | Sunny | 5 mph S | 0% |
| Tonight | 69°F | Mostly Clear | 6 mph SE | 0% |
| Wednesday | 89°F | Mostly Sunny then Isolated Showers And Thunderstorms | 6 mph S | 16% |
| Wednesday Night | 71°F | Chance Showers And Thunderstorms | 7 mph S | 76% |
| Thursday | 85°F | Showers And Thunderstorms | 6 mph S | 76% |
| Thursday Night | 69°F | Slight Chance Showers And Thunderstorms | 5 mph SE | 18% |
| Friday | 86°F | Slight Chance Showers And Thunderstorms then Partly Sunny | 5 mph SW | 18% |
| Friday Night | 70°F | Chance Showers And Thunderstorms | 5 mph S | 27% |
| Saturday | 89°F | Chance Showers And Thunderstorms then Mostly Sunny | 5 mph S | 27% |
| Saturday Night | 73°F | Mostly Clear | 7 mph S | 6% |
| Sunday | 91°F | Sunny | 8 mph S | 4% |
| Sunday Night | 75°F | Mostly Clear | 8 mph S | 5% |
| Monday | 92°F | Mostly Sunny | 9 mph SW | 5% |
| Monday Night | 76°F | Slight Chance Showers And Thunderstorms | 9 mph SW | 17% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Grafton, IL
Last spring frost
Apr 5
First fall frost
Oct 27
Growing season
203 days
Hardiness zone
6b
Explore more for Grafton, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, St Charles Co Ap, Mo (6 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.