Alton, IA Weather & Growing Conditions
Today
72°F
Patchy Smoke
Patchy smoke and scattered rain showers before 10am, then patchy smoke and showers and thunderstorms between 10am and 5pm, then patchy smoke and scattered showers and thunderstorms. Mostly cloudy, with a high near 72. North wind 5 to 10 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 72°F | Patchy Smoke | 5 to 10 mph N | 82% |
| Tonight | 54°F | Patchy Smoke then Mostly Cloudy | 0 to 5 mph NW | 49% |
| Wednesday | 75°F | Mostly Sunny | 0 to 5 mph ESE | 1% |
| Wednesday Night | 53°F | Mostly Clear | 0 to 5 mph SSE | 0% |
| Thursday | 82°F | Sunny | 0 to 10 mph S | 0% |
| Thursday Night | 61°F | Mostly Clear | 5 to 10 mph S | 3% |
| Friday | 86°F | Sunny | 5 to 10 mph SSW | 4% |
| Friday Night | 65°F | Mostly Clear | 5 to 10 mph S | 12% |
| Saturday | 90°F | Sunny | 5 to 15 mph S | 5% |
| Saturday Night | 67°F | Slight Chance Showers And Thunderstorms | 10 to 15 mph SSE | 20% |
| Sunday | 88°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 10 mph SE | 15% |
| Sunday Night | 67°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 10 to 15 mph ESE | 18% |
| Monday | 87°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 10 to 15 mph E | 18% |
| Monday Night | 67°F | Chance Showers And Thunderstorms | 15 mph ENE | 27% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Alton, IA
Last spring frost
Apr 30
First fall frost
Oct 3
Growing season
154 days
Hardiness zone
5a
Explore more for Alton, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Sioux Ctr 2 Se, Ia (9.6 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.