DeKalb, IL Weather & Growing Conditions
This Afternoon
60°F
Slight Chance Rain Showers
A slight chance of rain showers and a slight chance of drizzle. Cloudy. High near 60, with temperatures falling to around 54 in the afternoon. West southwest wind around 15 mph, with gusts as high as 25 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 60°F | Slight Chance Rain Showers | 15 mph WSW | 8% |
| Tonight | 45°F | Slight Chance Rain Showers then Cloudy | 15 mph SW | 9% |
| Thursday | 54°F | Chance Rain | 10 to 15 mph W | 48% |
| Thursday Night | 37°F | Chance Rain then Mostly Cloudy | 10 mph N | 25% |
| Friday | 48°F | Partly Sunny | 10 to 15 mph N | 0% |
| Friday Night | 29°F | Mostly Clear | 0 to 5 mph NNW | 0% |
| Saturday | 50°F | Sunny | 0 to 5 mph NW | 0% |
| Saturday Night | 31°F | Mostly Clear | 5 mph W | 0% |
| Sunday | 57°F | Sunny | 5 to 10 mph W | 1% |
| Sunday Night | 34°F | Mostly Clear | 0 to 5 mph W | 0% |
| Monday | 61°F | Sunny | 5 to 10 mph SW | 0% |
| Monday Night | 39°F | Clear | 5 to 10 mph WSW | 0% |
| Tuesday | 61°F | Sunny | 5 mph WNW | 1% |
| Tuesday Night | 37°F | Partly Cloudy | 0 to 5 mph NW | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for DeKalb, IL
Last spring frost
Apr 24
First fall frost
Oct 18
Growing season
177 days
Hardiness zone
5b
Explore more for DeKalb, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, De Kalb, Il (6.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 5, 2026.