Williamsfield, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Williamsfield, a village in Knox County, Illinois.
Tonight
68°F
Mostly Cloudy then Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms between 3am and 5am, then patchy fog and a chance of showers and thunderstorms. Mostly cloudy, with a low around 68. East southeast wind 6 to 9 mph, with gusts as high as 18 mph. Chance of precipitation is 30%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Williamsfield
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 68°F | Mostly Cloudy then Slight Chance Showers And Thunderstorms | 6 to 9 mph ESE | 29% |
| Saturday | 85°F | Patchy Fog then Chance Showers And Thunderstorms | 8 mph S | 34% |
| Saturday Night | 66°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 8 mph NE | 70% |
| Sunday | 75°F | Showers And Thunderstorms | 5 to 14 mph NE | 75% |
| Sunday Night | 58°F | Showers And Thunderstorms Likely | 12 to 15 mph NE | 71% |
| Monday | 66°F | Showers And Thunderstorms Likely | 16 mph ENE | 68% |
| Monday Night | 53°F | Chance Rain Showers | 12 to 16 mph NE | 43% |
| Tuesday | 65°F | Chance Rain Showers | 14 mph NE | 35% |
| Tuesday Night | 50°F | Mostly Cloudy | 6 to 13 mph NNE | 4% |
| Wednesday | 68°F | Partly Sunny | 9 mph NNE | 3% |
| Wednesday Night | 52°F | Partly Cloudy | 2 to 7 mph NNE | 3% |
| Thursday | 69°F | Mostly Sunny | 2 to 6 mph NNE | 4% |
| Thursday Night | 54°F | Partly Cloudy | 1 to 5 mph NE | 4% |
| Friday | 72°F | Mostly Sunny | 2 to 7 mph NE | 4% |
Forecast source: National Weather Service (api.weather.gov) for Williamsfield (40.926, -90.018). Updated through the day.
Growing snapshot for Williamsfield
Last spring frost
Apr 21
First fall frost
Oct 20
Growing season
181 days
Hardiness zone
5b
More local growing data for Williamsfield: nearby ZIP 61489 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Abingdon
Altona
East Galesburg
Galesburg
Gilson
Henderson
Knoxville
Maquon
Nekoma
Oak Run
Oneida
Rio
St. Augustine
Victoria
Wataga
Yates City
Climate data from the nearest NOAA station, Knoxville, Il (13.5 mi from Williamsfield). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.