DeKalb, IL Weather & Growing Conditions
Overnight
57°F
Chance Rain Showers
A chance of rain showers. Cloudy. Low around 57, with temperatures rising to around 59 overnight. South southwest wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 30%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 57°F | Chance Rain Showers | 15 mph SSW | 30% |
| Wednesday | 61°F | Patchy Drizzle | 15 mph SSW | 20% |
| Wednesday Night | 46°F | Patchy Drizzle | 15 mph SW | 15% |
| Thursday | 54°F | Chance Rain Showers | 10 to 15 mph WSW | 35% |
| Thursday Night | 40°F | Chance Rain Showers then Mostly Cloudy | 10 mph NW | 37% |
| Friday | 49°F | Partly Sunny | 10 to 15 mph N | 9% |
| Friday Night | 32°F | Partly Cloudy | 5 to 10 mph NNW | 0% |
| Saturday | 50°F | Sunny | 5 mph NW | 0% |
| Saturday Night | 33°F | Mostly Clear | 5 mph W | 1% |
| Sunday | 55°F | Sunny | 5 to 10 mph W | 5% |
| Sunday Night | 35°F | Mostly Clear | 5 mph W | 0% |
| Monday | 60°F | Sunny | 5 to 10 mph WSW | 0% |
| Monday Night | 40°F | Mostly Clear | 5 to 10 mph W | 1% |
| Tuesday | 61°F | Sunny | 5 mph WNW | 0% |
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 (2.4 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.