Delavan, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Delavan, a city in Tazewell County, Illinois.
Overnight
69°F
Partly Cloudy
Partly cloudy, with a low around 69. Southeast wind around 8 mph, with gusts as high as 17 mph.
7-day forecast for Delavan
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 69°F | Partly Cloudy | 8 mph SE | 14% |
| Saturday | 89°F | Slight Chance Showers And Thunderstorms then Mostly Cloudy | 8 mph S | 18% |
| Saturday Night | 68°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 7 mph SE | 43% |
| Sunday | 80°F | Showers And Thunderstorms Likely | 3 to 12 mph NNE | 63% |
| Sunday Night | 60°F | Showers And Thunderstorms Likely | 10 to 14 mph NE | 64% |
| Monday | 68°F | Showers And Thunderstorms Likely | 14 mph ENE | 64% |
| Monday Night | 55°F | Chance Showers And Thunderstorms | 10 to 15 mph NE | 47% |
| Tuesday | 66°F | Chance Rain Showers then Mostly Cloudy | 13 mph NE | 25% |
| Tuesday Night | 51°F | Mostly Cloudy | 6 to 12 mph NNE | 5% |
| Wednesday | 69°F | Mostly Sunny | 9 mph NNE | 4% |
| Wednesday Night | 53°F | Partly Cloudy | 3 to 8 mph NNE | 1% |
| Thursday | 70°F | Mostly Sunny | 3 to 7 mph NNE | 2% |
| Thursday Night | 55°F | Partly Cloudy | 2 to 6 mph NE | 3% |
| Friday | 73°F | Mostly Sunny | 3 to 7 mph NNE | 3% |
Forecast source: National Weather Service (api.weather.gov) for Delavan (40.371, -89.546). Updated through the day.
Growing snapshot for Delavan
Last spring frost
Apr 17
First fall frost
Oct 18
Growing season
182 days
Hardiness zone
6a
More local growing data for Delavan: nearby ZIP 61734 weather · frost dates · planting calendar · Illinois frost dates
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Washington
Climate data from the nearest NOAA station, Mason City 4Se, Il (16.1 mi from Delavan). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.