Williamson, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Williamson, a city in Lucas County, Iowa.
This Afternoon
84°F
Slight Chance Showers And Thunderstorms
A slight chance of rain showers between 3pm and 4pm, then a slight chance of showers and thunderstorms between 4pm and 5pm. Partly sunny. High near 84, with temperatures falling to around 82 in the afternoon. West southwest wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Williamson
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 84°F | Slight Chance Showers And Thunderstorms | 10 mph WSW | 19% |
| Tonight | 63°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 2 to 7 mph NNW | 69% |
| Sunday | 67°F | Chance Rain Showers then Chance Showers And Thunderstorms | 7 to 12 mph NNE | 50% |
| Sunday Night | 58°F | Slight Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 12 mph NE | 64% |
| Monday | 60°F | Rain Showers Likely | 12 mph NE | 64% |
| Monday Night | 52°F | Rain Showers Likely | 7 to 10 mph NE | 57% |
| Tuesday | 59°F | Chance Rain Showers then Partly Sunny | 9 mph NE | 33% |
| Tuesday Night | 46°F | Partly Cloudy | 6 mph NE | 4% |
| Wednesday | 63°F | Sunny | 5 mph NE | 2% |
| Wednesday Night | 51°F | Partly Cloudy | 3 mph E | 4% |
| Thursday | 65°F | Slight Chance Rain Showers | 3 mph ESE | 17% |
| Thursday Night | 56°F | Mostly Cloudy | 2 mph E | 11% |
| Friday | 68°F | Partly Sunny | 2 to 6 mph E | 11% |
| Friday Night | 56°F | Mostly Cloudy | 3 mph ESE | 8% |
Forecast source: National Weather Service (api.weather.gov) for Williamson (41.088, -93.257). Updated through the day.
Growing snapshot for Williamson
Last spring frost
May 5
First fall frost
Oct 5
Growing season
151 days
Hardiness zone
5b
More local growing data for Williamson: nearby ZIP 50272 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Chariton 1 E, Ia (5.1 mi from Williamson). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.