Decatur weather live forecast

Today's maximum temperature in Decatur is expected to be 31°C. Select a day from the live weather forecast for Decatur, Illinois, USA for more weather parameters.

Thursday
16th Jul
31

23

10

8
Friday
17th Jul
28

23

6

7
Saturday
18th Jul
31

23

6

8
Sunday
19th Jul
28

20

7

9
Monday
20th Jul
30

19

5

9

5-day weather forecast updated at 04:01 on Thursday 16th July 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 Thursday 16th July 2026

Expect isolated thunderstorms in Decatur, Illinois with a maximum temperature of 31°C, moderate levels of heat & humidity, maximum UV of 8 (Very High) and 10 hours of bright sunshine. There are 0-2 mm of rainfall expected with 51% chance of some rain and a light breeze of 9 kph from the south.

31
°C maximum temperature
23
°C minimum temperature
isolated thunderstorms
10
hours of sunshine
8
UV index (Very High)
51
% chance of some rain
<2
mm of rainfall expected
M
moderate heat & humidity
9
kph wind from S

Decatur weather for Friday 17th July 2026

Expect isolated thunderstorms in Decatur, Illinois with a maximum temperature of 28°C, low levels of heat & humidity, maximum UV of 7 (High) and 6 hours of bright sunshine. There are 5-10 mm of rainfall expected with 88% chance of some rain and a light breeze of 12 kph from the south-west.

28
°C maximum temperature
23
°C minimum temperature
isolated thunderstorms
6
hours of sunshine
7
UV index (High)
88
% chance of some rain
<10
mm of rainfall expected
L
low heat & humidity
12
kph wind from SW

Decatur weather for Saturday 18th July 2026

Expect isolated thunderstorms in Decatur, Illinois with a maximum temperature of 31°C, moderate levels of heat & humidity, maximum UV of 8 (Very High) and 6 hours of bright sunshine. There are 0-2 mm of rainfall expected with 52% chance of some rain and a moderate breeze of 21 kph from the west.

31
°C maximum temperature
23
°C minimum temperature
isolated thunderstorms
6
hours of sunshine
8
UV index (Very High)
52
% chance of some rain
<2
mm of rainfall expected
M
moderate heat & humidity
21
kph wind from W

Decatur weather for Sunday 19th July 2026

Expect broken clouds in Decatur, Illinois with a maximum temperature of 28°C, low levels of heat & humidity, maximum UV of 9 (Very High) and 7 hours of bright sunshine. There are 0 mm of rainfall expected and a gentle breeze of 13 kph from the north-east.

28
°C maximum temperature
20
°C minimum temperature
broken clouds
7
hours of sunshine
9
UV index (Very High)
0
mm of rainfall expected
L
low heat & humidity
13
kph wind from NE

Decatur weather for Monday 20th July 2026

Expect isolated thunderstorms in Decatur, Illinois with a maximum temperature of 30°C, moderate levels of heat & humidity, maximum UV of 9 (Very High) and 5 hours of bright sunshine. There are 2-5 mm of rainfall expected with 42% chance of some rain and a gentle breeze of 13 kph from the south-west.