Decatur weather live forecast

Tomorrow's maximum temperature in Decatur is expected to be 28°C.

5-day weather forecast updated at 04:01 on Friday 18th July 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 Friday 18th July 2025

Expect isolated thunderstorms in Decatur, Illinois with a maximum temperature of 28°C, low levels of heat & humidity, maximum UV of 7 (High) and 5 hours of bright sunshine. There are 0-2 mm of rainfall expected with 49% chance of some rain and little or no wind of 6 kph from the north-east.

  • 28°C maximum temperature28
    °C maximum temperature
  • 20°C minimum temperature20
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 5 hours of bright sunshine5
    hours of sunshine
  • UV (maximum) index 7 (High)7
    UV index (High)
  • 49% chance of some rain49
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • Low heat & humidityL
    low heat & humidity
  • Little or no wind of 6 kph from the North-East6
    kph wind from NE

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Decatur weather for Saturday 19th July 2025

Expect isolated thunderstorms in Decatur, Illinois with a maximum temperature of 30°C, moderate levels of heat & humidity, maximum UV of 6 (High) and 6 hours of bright sunshine. There are 0-2 mm of rainfall expected with 80% chance of some rain and a light breeze of 8 kph from the south-west.

  • 30°C maximum temperature30
    °C maximum temperature
  • 23°C minimum temperature23
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 6 hours of bright sunshine6
    hours of sunshine
  • UV (maximum) index 6 (High)6
    UV index (High)
  • 80% chance of some rain80
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Light breeze of 8 kph from the South-West8
    kph wind from SW

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Decatur weather for Sunday 20th July 2025

Expect isolated thunderstorms in Decatur, Illinois with a maximum temperature of 30°C, moderate levels of heat & humidity, maximum UV of 6 (High) and 3 hours of bright sunshine. There are 2-5 mm of rainfall expected with 67% chance of some rain and little or no wind of 5 kph from the east.

  • 30°C maximum temperature30
    °C maximum temperature
  • 23°C minimum temperature23
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 3 hours of bright sunshine3
    hours of sunshine
  • UV (maximum) index 6 (High)6
    UV index (High)
  • 67% chance of some rain67
    % chance of some rain
  • 2-5 mm of rainfall expected<5
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Little or no wind of 5 kph from the East5
    kph wind from E

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Decatur weather for Monday 21st July 2025

Expect isolated thunderstorms in Decatur, Illinois with a maximum temperature of 29°C, moderate levels of heat & humidity, maximum UV of 6 (High) and 5 hours of bright sunshine. There are 10-20 mm of rainfall expected with 65% chance of some rain and little or no wind of 5 kph from the south-east.

  • 29°C maximum temperature29
    °C maximum temperature
  • 23°C minimum temperature23
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 5 hours of bright sunshine5
    hours of sunshine
  • UV (maximum) index 6 (High)6
    UV index (High)
  • 65% chance of some rain65
    % chance of some rain
  • 10-20 mm of rainfall expected<20
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Little or no wind of 5 kph from the South-East5
    kph wind from SE

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Decatur weather for Tuesday 22nd July 2025

Expect isolated thunderstorms in Decatur, Illinois with a maximum temperature of 32°C, high levels of heat & humidity, maximum UV of 8 (Very High) and 6 hours of bright sunshine. There are 2-5 mm of rainfall expected with 51% chance of some rain and little or no wind of 6 kph from the south-east.

  • 32°C maximum temperature32
    °C maximum temperature
  • 24°C minimum temperature24
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 6 hours of bright sunshine6
    hours of sunshine
  • UV (maximum) index 8 (Very High)8
    UV index (Very High)
  • 51% chance of some rain51
    % chance of some rain
  • 2-5 mm of rainfall expected<5
    mm of rainfall expected
  • High heat & humidityH
    high heat & humidity
  • Little or no wind of 6 kph from the South-East6
    kph wind from SE

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

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