Delavan, IL Weather & Growing Conditions
Overnight
56°F
Slight Chance Light Rain
A slight chance of rain before 5am. Mostly cloudy, with a low around 56. South southwest wind around 13 mph, with gusts as high as 23 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 56°F | Slight Chance Light Rain | 13 mph SSW | 19% |
| Wednesday | 60°F | Slight Chance Drizzle | 15 mph SW | 10% |
| Wednesday Night | 45°F | Slight Chance Drizzle then Mostly Cloudy | 13 mph WSW | 10% |
| Thursday | 59°F | Mostly Cloudy then Slight Chance Light Rain | 10 to 14 mph WSW | 17% |
| Thursday Night | 44°F | Chance Light Rain | 6 to 9 mph NW | 25% |
| Friday | 53°F | Partly Sunny | 12 mph N | 6% |
| Friday Night | 33°F | Partly Cloudy | 2 to 8 mph NNW | 0% |
| Saturday | 53°F | Sunny | 2 to 6 mph NW | 0% |
| Saturday Night | 33°F | Mostly Clear | 3 mph WNW | 1% |
| Sunday | 59°F | Sunny | 2 to 8 mph W | 1% |
| Sunday Night | 35°F | Clear | 5 mph WSW | 1% |
| Monday | 64°F | Sunny | 2 to 8 mph SW | 0% |
| Monday Night | 40°F | Mostly Clear | 2 to 6 mph SW | 0% |
| Tuesday | 67°F | Sunny | 2 to 6 mph WNW | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Delavan, IL
Last spring frost
Apr 17
First fall frost
Oct 18
Growing season
182 days
Hardiness zone
6a
Explore more for Delavan, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Mason City 4Se, Il (16.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.