Alton, MO Weather & Growing Conditions
Today
91°F
Sunny
Sunny. High near 91, with temperatures falling to around 89 in the afternoon. Heat index values as high as 94. Southeast wind around 2 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 91°F | Sunny | 2 mph SE | 0% |
| Tonight | 67°F | Mostly Clear | 0 to 3 mph SE | 0% |
| Wednesday | 93°F | Sunny | 0 to 3 mph SE | 0% |
| Wednesday Night | 71°F | Partly Cloudy | 1 to 5 mph SE | 14% |
| Thursday | 94°F | Chance Showers And Thunderstorms | 1 to 5 mph S | 32% |
| Thursday Night | 71°F | Chance Showers And Thunderstorms | 1 to 5 mph S | 49% |
| Friday | 91°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 3 mph S | 67% |
| Friday Night | 70°F | Chance Showers And Thunderstorms | 2 mph SW | 41% |
| Saturday | 92°F | Chance Showers And Thunderstorms | 0 to 3 mph S | 30% |
| Saturday Night | 70°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 3 mph S | 19% |
| Sunday | 93°F | Sunny | 1 to 5 mph S | 3% |
| Sunday Night | 71°F | Mostly Clear | 5 mph S | 2% |
| Monday | 95°F | Sunny | 2 to 6 mph S | 4% |
| Monday Night | 72°F | Mostly Clear | 2 to 6 mph S | 4% |
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 (10.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.