Alton, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Alton, a city in Madison County, Illinois.
Tonight
54°F
Chance Light Rain
A chance of rain before 3am, then a slight chance of drizzle. Mostly cloudy, with a low around 54. Southwest wind around 12 mph, with gusts as high as 22 mph. Chance of precipitation is 50%.
7-day forecast for Alton
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 54°F | Chance Light Rain | 12 mph SW | 47% |
| Wednesday | 62°F | Slight Chance Drizzle then Mostly Cloudy | 9 to 14 mph W | 12% |
| Wednesday Night | 45°F | Partly Cloudy | 5 to 8 mph W | 1% |
| Thursday | 63°F | Sunny | 7 to 13 mph W | 2% |
| Thursday Night | 44°F | Mostly Cloudy | 6 mph NW | 10% |
| Friday | 58°F | Mostly Cloudy | 6 to 10 mph NW | 5% |
| Friday Night | 39°F | Partly Cloudy | 2 to 8 mph N | 1% |
| Saturday | 56°F | Mostly Sunny | 5 mph NW | 0% |
| Saturday Night | 37°F | Partly Cloudy | 2 mph W | 1% |
| Sunday | 62°F | Sunny | 2 to 8 mph W | 7% |
| Sunday Night | 37°F | Mostly Clear | 2 to 6 mph W | 4% |
| Monday | 66°F | Sunny | 2 to 8 mph W | 2% |
| Monday Night | 41°F | Mostly Clear | 5 mph SW | 1% |
| Tuesday | 68°F | Sunny | 3 to 7 mph W | 0% |
Forecast source: National Weather Service (api.weather.gov) for Alton (38.904, -90.151). Updated through the day.
Growing snapshot for Alton
Last spring frost
Apr 4
First fall frost
Nov 5
Growing season
214 days
Hardiness zone
7a
More local growing data for Alton: nearby ZIP 62002 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Alhambra
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East Alton
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Highland
Holiday Shores
Livingston
Madison
Marine
Maryville
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Pontoon Beach
Prairietown
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Wood River
Climate data from the nearest NOAA station, Alton - Melvin Price L&D, Il (5.1 mi from Alton). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.