National Weather Service Forecast for: Decatur IL
Issued by: National Weather Service Lincoln, IL
Updated: 12:36 pm CDT Oct 6, 2026
 
This
Afternoon
This Afternoon: Sunny, with a high near 78. South southwest wind around 10 mph, with gusts as high as 17 mph.
Sunny
 Tonight

Tonight: Clear, with a low around 54. South wind around 8 mph, with gusts as high as 15 mph.
Clear
 Wednesday

Wednesday: Sunny, with a high near 84. Southwest wind 7 to 10 mph becoming west northwest in the afternoon. Winds could gust as high as 15 mph.
Sunny
 Wednesday
Night
Wednesday Night: Mostly clear, with a low around 53. North northwest wind around 6 mph becoming calm after midnight.
Mostly Clear
 Thursday

Thursday: Sunny, with a high near 77. Calm wind becoming north northwest 5 to 8 mph in the morning.
Sunny
 Thursday
Night
Thursday Night: Mostly clear, with a low around 48. North wind around 6 mph becoming calm in the evening.
Mostly Clear
 Friday

Friday: Sunny, with a high near 79. Southeast wind 3 to 7 mph.
Sunny
 Friday
Night
Friday Night: Mostly clear, with a low around 54.
Mostly Clear
 Saturday

Saturday: Sunny, with a high near 85.
Sunny
Hi 78 °F Lo 54 °F Hi 84 °F Lo 53 °F Hi 77 °F Lo 48 °F Hi 79 °F Lo 54 °F Hi 85 °F

 

This Afternoon
 
 Sunny, with a high near 78. South southwest wind around 10 mph, with gusts as high as 17 mph.
Tonight
 
 Clear, with a low around 54. South wind around 8 mph, with gusts as high as 15 mph.
Wednesday
 
 Sunny, with a high near 84. Southwest wind 7 to 10 mph becoming west northwest in the afternoon. Winds could gust as high as 15 mph.
Wednesday Night
 
 Mostly clear, with a low around 53. North northwest wind around 6 mph becoming calm after midnight.
Thursday
 
 Sunny, with a high near 77. Calm wind becoming north northwest 5 to 8 mph in the morning.
Thursday Night
 
 Mostly clear, with a low around 48. North wind around 6 mph becoming calm in the evening.
Friday
 
 Sunny, with a high near 79. Southeast wind 3 to 7 mph.
Friday Night
 
 Mostly clear, with a low around 54.
Saturday
 
 Sunny, with a high near 85.
Saturday Night
 
 Partly cloudy, with a low around 59.
Sunday
 
 Mostly sunny, with a high near 82.
Sunday Night
 
 Mostly clear, with a low around 59.
Columbus Day
 
 Sunny, with a high near 85.

 

Forecast from NOAA-NWS for Decatur IL.