Alton, MO Weather & Growing Conditions
Tonight
70°F
Clear
Clear, with a low around 70. Heat index values as high as 98. Southwest wind around 2 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 70°F | Clear | 2 mph SW | 5% |
| Saturday | 100°F | Sunny | 2 to 6 mph SW | 1% |
| Saturday Night | 70°F | Mostly Clear | 3 mph SW | 0% |
| Sunday | 99°F | Mostly Sunny | 2 to 6 mph W | 1% |
| Sunday Night | 69°F | Mostly Cloudy then Slight Chance Rain Showers | 3 mph NW | 16% |
| Monday | 92°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 5 mph N | 52% |
| Monday Night | 63°F | Chance Showers And Thunderstorms | 5 mph N | 52% |
| Tuesday | 83°F | Partly Sunny | 6 mph N | 13% |
| Tuesday Night | 56°F | Partly Cloudy | 3 to 7 mph N | 7% |
| Wednesday | 81°F | Mostly Sunny | 5 mph N | 2% |
| Wednesday Night | 55°F | Mostly Clear | 5 mph NE | 0% |
| Thursday | 82°F | Sunny | 5 mph NE | 3% |
| Thursday Night | 56°F | Partly Cloudy | 3 mph NE | 3% |
| Friday | 82°F | Mostly Sunny | 5 mph NE | 6% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Alton, MO
Last spring frost
Apr 17
First fall frost
Oct 21
Growing season
187 days
Hardiness zone
7a
Explore more for Alton, MO: full frost dates · planting calendar · Missouri frost dates
Climate data from the nearest NOAA station, Alton, Mo (2.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.