Williamson, IA Weather & Growing Conditions
Tonight
47°F
Cloudy
Cloudy. Low around 47, with temperatures rising to around 49 overnight. West wind 10 to 15 mph, with gusts as high as 21 mph. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 47°F | Cloudy | 10 to 15 mph W | 14% |
| Wednesday | 53°F | Mostly Cloudy | 13 to 16 mph W | 12% |
| Wednesday Night | 43°F | Mostly Cloudy | 12 mph W | 5% |
| Thursday | 52°F | Chance Rain Showers | 10 mph WNW | 35% |
| Thursday Night | 41°F | Slight Chance Rain Showers then Mostly Cloudy | 8 mph NNW | 18% |
| Friday | 52°F | Partly Sunny | 3 to 8 mph N | 5% |
| Friday Night | 35°F | Partly Cloudy | 2 mph N | 0% |
| Saturday | 56°F | Partly Sunny | 1 to 5 mph WSW | 3% |
| Saturday Night | 37°F | Mostly Clear | 5 mph W | 4% |
| Sunday | 62°F | Sunny | 6 mph W | 5% |
| Sunday Night | 39°F | Mostly Clear | 7 mph SW | 1% |
| Monday | 65°F | Sunny | 7 to 10 mph SW | 0% |
| Monday Night | 42°F | Mostly Clear | 6 mph W | 0% |
| Tuesday | 64°F | Sunny | 6 mph NNW | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Williamson, IA
Last spring frost
May 5
First fall frost
Oct 5
Growing season
151 days
Hardiness zone
5b
Explore more for Williamson, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Chariton 1 E, Ia (5.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.