Decatur weather live forecast

Today's maximum temperature in Decatur is expected to be 30°C. Select a day from the live weather forecast for Decatur, Illinois, USA for more weather parameters.

Monday
14th Sep
30

17

9

6
Tuesday
15th Sep
28

18

9

6

5-day weather forecast updated at 04:01 on Thursday 10th September 2026 GMT

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The 5-day weather forecast for Illinois (Decatur) is provided by the Swiss meteorological agency, meteoblue. Find out more about our data sources.

Decatur weather forecast by day

Below are the detailed weather forecasts for Decatur for the next 5 days.

Decatur weather for Monday 14th September 2026

Expect scattered clouds in Decatur, Illinois with a maximum temperature of 30°C, moderate levels of heat & humidity, maximum UV of 6 (High) and 9 hours of bright sunshine. There are 0 mm of rainfall expected and a moderate breeze of 22 kph from the south.

30
°C maximum temperature
17
°C minimum temperature
scattered clouds
9
hours of sunshine
6
UV index (High)
0
mm of rainfall expected
M
moderate heat & humidity
22
kph wind from S

Decatur weather for Tuesday 15th September 2026

Expect isolated thunderstorms in Decatur, Illinois with a maximum temperature of 28°C, low levels of heat & humidity, maximum UV of 6 (High) and 9 hours of bright sunshine. There are 0-2 mm of rainfall expected with 60% chance of some rain and a moderate breeze of 20 kph from the west.