Decatur weather live forecast

Today's maximum temperature in Decatur is expected to be 32°C. Select a day from the live weather forecast for Decatur, Illinois, USA for more weather parameters.

5-day weather forecast updated at 04:01 on Wednesday 17th September 2025 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 Wednesday 17th September 2025

Expect clear skies in Decatur, Illinois with a maximum temperature of 32°C, moderate levels of heat & humidity, maximum UV of 7 (High) and 11 hours of bright sunshine. There are 0 mm of rainfall expected and little or no wind of 4 kph from the north-east.

  • 32°C maximum temperature32
    °C maximum temperature
  • 17°C minimum temperature17
    °C minimum temperature
  • Clear skies
    clear skies
  • 11 hours of bright sunshine11
    hours of sunshine
  • UV (maximum) index 7 (High)7
    UV index (High)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Little or no wind of 4 kph from the North-East4
    kph wind from NE

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Decatur weather for Thursday 18th September 2025

Expect clear skies in Decatur, Illinois with a maximum temperature of 31°C, moderate levels of heat & humidity, maximum UV of 6 (High) and 12 hours of bright sunshine. There are 0 mm of rainfall expected and little or no wind of 3 kph from the east.

  • 31°C maximum temperature31
    °C maximum temperature
  • 17°C minimum temperature17
    °C minimum temperature
  • Clear skies
    clear skies
  • 12 hours of bright sunshine12
    hours of sunshine
  • UV (maximum) index 6 (High)6
    UV index (High)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Little or no wind of 3 kph from the East3
    kph wind from E

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Decatur weather for Friday 19th September 2025

Expect isolated thunderstorms in Decatur, Illinois with a maximum temperature of 31°C, moderate levels of heat & humidity, maximum UV of 5 (Moderate) and 6 hours of bright sunshine. There are 0-2 mm of rainfall expected with 34% chance of some rain and little or no wind of 4 kph from the south-east.

  • 31°C maximum temperature31
    °C maximum temperature
  • 18°C minimum temperature18
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 6 hours of bright sunshine6
    hours of sunshine
  • UV (maximum) index 5 (Moderate)5
    UV index (Moderate)
  • 34% chance of some rain34
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Little or no wind of 4 kph from the South-East4
    kph wind from SE

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Decatur weather for Saturday 20th September 2025

Expect mostly cloudy with light rain in Decatur, Illinois with a maximum temperature of 28°C, low levels of heat & humidity, maximum UV of 5 (Moderate) and 4 hours of bright sunshine. There are 0-2 mm of rainfall expected with 38% chance of some rain and a light breeze of 7 kph from the south.

  • 28°C maximum temperature28
    °C maximum temperature
  • 19°C minimum temperature19
    °C minimum temperature
  • Mostly cloudy with light rain
    mostly cloudy with light rain
  • 4 hours of bright sunshine4
    hours of sunshine
  • UV (maximum) index 5 (Moderate)5
    UV index (Moderate)
  • 38% chance of some rain38
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • Low heat & humidityL
    low heat & humidity
  • Light breeze of 7 kph from the South7
    kph wind from S

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Decatur weather for Sunday 21st September 2025

Expect isolated thunderstorms in Decatur, Illinois with a maximum temperature of 26°C, low levels of heat & humidity, maximum UV of 5 (Moderate) and 4 hours of bright sunshine. There are 5-10 mm of rainfall expected with 59% chance of some rain and a light breeze of 10 kph from the south.

  • 26°C maximum temperature26
    °C maximum temperature
  • 19°C minimum temperature19
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 4 hours of bright sunshine4
    hours of sunshine
  • UV (maximum) index 5 (Moderate)5
    UV index (Moderate)
  • 59% chance of some rain59
    % chance of some rain
  • 5-10 mm of rainfall expected<10
    mm of rainfall expected
  • Low heat & humidityL
    low heat & humidity
  • Light breeze of 10 kph from the South10
    kph wind from S

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Metric (°C / mm)  |  Imperial (°F / inches)

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