Alton, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Alton, a city in Madison County, Illinois.
Overnight
65°F
Patchy Fog
Patchy fog. Clear, with a low around 65. East wind around 1 mph.
7-day forecast for Alton
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 65°F | Patchy Fog | 1 mph E | 0% |
| Tuesday | 88°F | Patchy Fog then Sunny | 5 mph SE | 0% |
| Tuesday Night | 68°F | Mostly Clear | 5 mph SE | 0% |
| Wednesday | 90°F | Sunny | 2 to 7 mph S | 12% |
| Wednesday Night | 71°F | Chance Showers And Thunderstorms | 7 mph S | 74% |
| Thursday | 86°F | Showers And Thunderstorms Likely | 6 mph SW | 74% |
| Thursday Night | 70°F | Chance Showers And Thunderstorms | 5 mph SE | 28% |
| Friday | 86°F | Chance Showers And Thunderstorms then Partly Sunny | 5 mph SW | 28% |
| Friday Night | 70°F | Chance Showers And Thunderstorms | 5 mph S | 31% |
| Saturday | 89°F | Chance Showers And Thunderstorms then Mostly Sunny | 2 to 6 mph S | 31% |
| Saturday Night | 73°F | Mostly Clear | 6 mph S | 6% |
| Sunday | 92°F | Sunny | 5 to 9 mph S | 6% |
| Sunday Night | 74°F | Mostly Clear | 8 mph S | 5% |
| Monday | 93°F | Mostly Sunny | 6 to 9 mph SW | 5% |
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
Bethalto
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East Alton
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Godfrey
Granite City
Grantfork
Hamel
Hartford
Highland
Holiday Shores
Livingston
Madison
Marine
Maryville
Mitchell
Moro
New Douglas
Pontoon Beach
Prairietown
Rosewood Heights
Roxana
South Roxana
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Troy
Venice
Williamson
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 Aug 4, 2026.