Alton, IA Weather & Growing Conditions
Today
47°F
Rain Showers Likely
Rain showers likely. Cloudy, with a high near 47. West northwest wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 60%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 47°F | Rain Showers Likely | 15 mph WNW | 55% |
| Tonight | 38°F | Chance Rain Showers | 10 to 15 mph NW | 44% |
| Thursday | 47°F | Mostly Cloudy | 10 to 15 mph NNW | 7% |
| Thursday Night | 32°F | Mostly Cloudy | 0 to 10 mph N | 0% |
| Friday | 46°F | Mostly Sunny | 0 mph | 0% |
| Friday Night | 29°F | Partly Cloudy | 0 mph | 0% |
| Saturday | 51°F | Mostly Sunny | 0 to 5 mph SSW | 0% |
| Saturday Night | 34°F | Mostly Clear | 0 to 5 mph WSW | 0% |
| Sunday | 56°F | Sunny | 0 to 5 mph WSW | 0% |
| Sunday Night | 37°F | Mostly Clear | 5 mph SSW | 0% |
| Monday | 61°F | Sunny | 5 to 10 mph WSW | 0% |
| Monday Night | 38°F | Mostly Clear | 0 to 5 mph NW | 0% |
| Tuesday | 59°F | Mostly Sunny | 0 to 5 mph WNW | 0% |
| Tuesday Night | 41°F | Partly Cloudy | 0 to 5 mph SSE | 1% |
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 Nov 4, 2026.