Weather World
Cortland, IL 7-Day Night Weather Forecast
Quick Weather Clicks
Settings
Sun & Moon
Weather Quote O' the Day
Cortland, IL Weather Forecast
Cortland, IL Weather Forecast Date: 346 PM CDT Wed Sep 23 2026
The area/counties/county of: De Kalb, including the cities of: Dekalb and Sycamore.or toggle through each period.
Late This Afternoon... Mostly cloudy. Temperatures in the mid 60s. Northeast winds 10 to 15 mph.
Tonight... Mostly cloudy. Lows in the mid 50s. Northeast winds 5 to 10 mph.
Thursday... Partly cloudy. Highs in the upper 60s. East winds 5 to 10 mph.
Thursday Night... Mostly cloudy. Lows in the mid 50s. East winds around 5 mph.
Friday... Mostly cloudy in the morning, then becoming partly cloudy. Highs in the upper 60s. East winds around 5 mph.
Friday Night... Partly cloudy. Lows around 50. East winds around 5 mph.
Saturday... Mostly cloudy. Highs in the mid 60s.
Saturday Night... Mostly cloudy. A slight chance of showers after midnight. Lows in the lower 50s. Chance of precipitation 20%.
Sunday... Mostly cloudy. Highs in the mid 60s.
Sunday Night... Mostly cloudy in the evening, then becoming partly cloudy. Lows in the lower 50s.
Monday... Partly cloudy. Highs in the upper 60s.
Monday Night... Mostly clear in the evening, then becoming partly cloudy. Lows in the mid 50s.
Tuesday... Mostly cloudy. A chance of showers in the afternoon. Highs in the lower 70s. Chance of precipitation 40%.
Tuesday Night... Showers likely. Lows in the upper 50s. Chance of precipitation 60%.
POP = Probability of Precipitation
Cortland Radar Loop
Use the map search tool if you want to place a location marker on the radar map...