Alton, IL Weather & Growing Conditions
Today
97°F
Partly Sunny
Partly sunny, with a high near 97. Southwest wind 3 to 8 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 97°F | Partly Sunny | 3 to 8 mph SW | 6% |
| Tonight | 72°F | Partly Cloudy | 5 mph SW | 4% |
| Sunday | 92°F | Chance Rain Showers then Chance Showers And Thunderstorms | 3 to 8 mph NW | 36% |
| Sunday Night | 65°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 7 to 12 mph NE | 65% |
| Monday | 77°F | Showers And Thunderstorms Likely | 8 to 13 mph NE | 66% |
| Monday Night | 57°F | Chance Showers And Thunderstorms | 8 to 13 mph NE | 48% |
| Tuesday | 71°F | Slight Chance Rain Showers then Partly Sunny | 13 mph NE | 20% |
| Tuesday Night | 53°F | Mostly Cloudy | 6 to 13 mph N | 8% |
| Wednesday | 74°F | Mostly Sunny | 8 to 12 mph N | 1% |
| Wednesday Night | 54°F | Partly Cloudy | 3 to 10 mph N | 0% |
| Thursday | 77°F | Mostly Sunny | 5 to 9 mph N | 1% |
| Thursday Night | 56°F | Partly Cloudy | 3 to 9 mph NE | 3% |
| Friday | 78°F | Mostly Sunny | 5 to 9 mph NE | 6% |
| Friday Night | 56°F | Partly Cloudy | 3 to 9 mph NE | 5% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Alton, IL
Last spring frost
Apr 4
First fall frost
Nov 5
Growing season
214 days
Hardiness zone
7a
Explore more for Alton, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Alton - Melvin Price L&D, Il (5.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.