Williamstown, MO Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Williamstown, a community in Lewis County, Missouri.
Overnight
51°F
Slight Chance Drizzle
A slight chance of drizzle. Cloudy, with a low around 51. West wind around 12 mph.
7-day forecast for Williamstown
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 51°F | Slight Chance Drizzle | 12 mph W | 13% |
| Wednesday | 55°F | Slight Chance Drizzle | 13 mph W | 13% |
| Wednesday Night | 44°F | Mostly Cloudy | 9 mph W | 2% |
| Thursday | 56°F | Mostly Cloudy | 7 to 10 mph W | 7% |
| Thursday Night | 44°F | Chance Light Rain then Mostly Cloudy | 7 mph NW | 26% |
| Friday | 52°F | Partly Sunny | 5 to 8 mph N | 1% |
| Friday Night | 32°F | Partly Cloudy | 3 mph N | 0% |
| Saturday | 53°F | Mostly Sunny | 1 to 5 mph NW | 0% |
| Saturday Night | 35°F | Mostly Clear | 3 mph W | 2% |
| Sunday | 60°F | Sunny | 6 mph W | 1% |
| Sunday Night | 36°F | Clear | 2 mph W | 0% |
| Monday | 65°F | Sunny | 2 to 7 mph SW | 0% |
| Monday Night | 42°F | Clear | 5 mph W | 0% |
| Tuesday | 66°F | Sunny | 5 mph NW | 0% |
Forecast source: National Weather Service (api.weather.gov) for Williamstown (40.241, -91.798). Updated through the day.
Growing snapshot for Williamstown
Last spring frost
Apr 11
First fall frost
Oct 23
Growing season
194 days
Hardiness zone
6a
More local growing data for Williamstown: nearby ZIP 63473 weather · frost dates · planting calendar · Missouri frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Canton L&D 20, Mo (15.3 mi from Williamstown). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.