National Weather Service Forecast for: Decatur IL
Issued by: National Weather Service Lincoln, IL
Updated: 12:06 pm CDT Mar 19, 2026
 
This
Afternoon
This Afternoon: Sunny, with a high near 71. South southeast wind around 7 mph.
Sunny
 Tonight

Tonight: Partly cloudy, with a low around 48. South southeast wind 5 to 8 mph, with gusts as high as 16 mph.
Partly Cloudy
 Friday

Friday: Mostly sunny, with a high near 76. Southwest wind 8 to 14 mph becoming west northwest in the afternoon. Winds could gust as high as 22 mph.
Mostly Sunny
 Friday
Night
Friday Night: Mostly cloudy, with a low around 46. Northwest wind 5 to 8 mph becoming northeast after midnight.
Mostly Cloudy
 Saturday

Saturday: Sunny, with a high near 75. East northeast wind 5 to 7 mph becoming southwest in the afternoon.
Sunny
 Saturday
Night
Saturday Night: Mostly clear, with a low around 55. South wind 6 to 11 mph, with gusts as high as 20 mph.
Mostly Clear
 Sunday

Sunday: Mostly sunny, with a high near 79. South southwest wind 13 to 18 mph becoming west northwest in the afternoon. Winds could gust as high as 29 mph.
Mostly Sunny
 Sunday
Night
Sunday Night: Partly cloudy, with a low around 35.
Partly Cloudy
 Monday

Monday: Sunny, with a high near 50.
Sunny
Hi 71 °F Lo 48 °F Hi 76 °F Lo 46 °F Hi 75 °F Lo 55 °F Hi 79 °F Lo 35 °F Hi 50 °F

 

This Afternoon
 
 Sunny, with a high near 71. South southeast wind around 7 mph.
Tonight
 
 Partly cloudy, with a low around 48. South southeast wind 5 to 8 mph, with gusts as high as 16 mph.
Friday
 
 Mostly sunny, with a high near 76. Southwest wind 8 to 14 mph becoming west northwest in the afternoon. Winds could gust as high as 22 mph.
Friday Night
 
 Mostly cloudy, with a low around 46. Northwest wind 5 to 8 mph becoming northeast after midnight.
Saturday
 
 Sunny, with a high near 75. East northeast wind 5 to 7 mph becoming southwest in the afternoon.
Saturday Night
 
 Mostly clear, with a low around 55. South wind 6 to 11 mph, with gusts as high as 20 mph.
Sunday
 
 Mostly sunny, with a high near 79. South southwest wind 13 to 18 mph becoming west northwest in the afternoon. Winds could gust as high as 29 mph.
Sunday Night
 
 Partly cloudy, with a low around 35.
Monday
 
 Sunny, with a high near 50.
Monday Night
 
 Mostly cloudy, with a low around 32.
Tuesday
 
 Mostly cloudy, with a high near 55.
Tuesday Night
 
 Mostly cloudy, with a low around 37.
Wednesday
 
 Mostly sunny, with a high near 65.

 

Forecast from NOAA-NWS for Decatur IL.