Williamson, IA Weather & Growing Conditions
Today
87°F
Partly Sunny then Chance Showers And Thunderstorms
A chance of showers and thunderstorms after noon. Partly sunny. High near 87, with temperatures falling to around 85 in the afternoon. West northwest wind around 7 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 87°F | Partly Sunny then Chance Showers And Thunderstorms | 7 mph WNW | 44% |
| Tonight | 64°F | Showers And Thunderstorms | 6 to 9 mph NNE | 82% |
| Wednesday | 74°F | Chance Showers And Thunderstorms then Showers And Thunderstorms | 8 mph NNE | 89% |
| Wednesday Night | 59°F | Showers And Thunderstorms Likely | 2 to 8 mph NNE | 58% |
| Thursday | 80°F | Chance Rain Showers then Mostly Sunny | 5 mph NE | 28% |
| Thursday Night | 62°F | Mostly Clear | 3 mph ESE | 5% |
| Friday | 85°F | Sunny | 6 mph S | 7% |
| Friday Night | 67°F | Mostly Clear | 6 mph SSE | 14% |
| Saturday | 89°F | Sunny | 6 to 9 mph SSW | 8% |
| Saturday Night | 72°F | Mostly Clear | 9 to 14 mph SSW | 10% |
| Sunday | 91°F | Mostly Sunny | 14 mph SSW | 10% |
| Sunday Night | 72°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 13 mph S | 22% |
| Monday | 91°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 15 mph SSW | 22% |
| Monday Night | 73°F | Chance Showers And Thunderstorms | 12 to 15 mph S | 27% |
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 Aug 4, 2026.