Illinois weather live forecast

Today's maximum temperature in Illinois is expected to be 27°C. Select a day from the live weather forecast for Illinois (Chicago), USA for more weather parameters.

5-day weather forecast updated at 04:01 on Thursday 18th September 2025 GMT

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

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Below are temperatures expected today at popular countries, regions and places in Illinois. Select a destination to see the detailed weather forecast for today, tomorrow and the outlook for the next five days.

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Illinois weather forecast by day

Below are the detailed weather forecasts for Illinois for the next 5 days. The forecasts shown are for Chicago and may not represent the whole of Illinois. Browse more destinations in Illinois to view more weather forecasts.

Illinois weather for Thursday 18th September 2025

Expect scattered clouds in Illinois with a maximum temperature of 27°C, low levels of heat & humidity, maximum UV of 6 (High) and 11 hours of bright sunshine. There are 0 mm of rainfall expected and little or no wind of 6 kph from the east.

  • 27°C maximum temperature27
    °C maximum temperature
  • 20°C minimum temperature20
    °C minimum temperature
  • Scattered clouds
    scattered clouds
  • 11 hours of bright sunshine11
    hours of sunshine
  • UV (maximum) index 6 (High)6
    UV index (High)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • Low heat & humidityL
    low heat & humidity
  • Little or no wind of 6 kph from the East6
    kph wind from E

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Illinois weather for Friday 19th September 2025

Expect isolated thunderstorms in Illinois with a maximum temperature of 26°C, maximum UV of 5 (Moderate) and 9 hours of bright sunshine. There are 0-2 mm of rainfall expected with 25% chance of some rain and little or no wind of 6 kph from the east.

  • 26°C maximum temperature26
    °C maximum temperature
  • 21°C minimum temperature21
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 9 hours of bright sunshine9
    hours of sunshine
  • UV (maximum) index 5 (Moderate)5
    UV index (Moderate)
  • 25% chance of some rain25
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • 26°C wind chill26
    °C wind chill
  • Little or no wind of 6 kph from the East6
    kph wind from E

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Illinois weather for Saturday 20th September 2025

Expect isolated thunderstorms in Illinois with a maximum temperature of 25°C, maximum UV of 3 (Moderate) and 4 hours of bright sunshine. There are 2-5 mm of rainfall expected with 35% chance of some rain and a light breeze of 7 kph from the south-east.

  • 25°C maximum temperature25
    °C maximum temperature
  • 21°C minimum temperature21
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 4 hours of bright sunshine4
    hours of sunshine
  • UV (maximum) index 3 (Moderate)3
    UV index (Moderate)
  • 35% chance of some rain35
    % chance of some rain
  • 2-5 mm of rainfall expected<5
    mm of rainfall expected
  • 25°C wind chill25
    °C wind chill
  • Light breeze of 7 kph from the South-East7
    kph wind from SE

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Illinois weather for Sunday 21st September 2025

Expect isolated thunderstorms in Illinois with a maximum temperature of 24°C, maximum UV of 2 (Low) and 4 hours of bright sunshine. There are 0-2 mm of rainfall expected with 62% chance of some rain and a light breeze of 10 kph from the south.

  • 24°C maximum temperature24
    °C maximum temperature
  • 21°C minimum temperature21
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 4 hours of bright sunshine4
    hours of sunshine
  • UV (maximum) index 2 (Low)2
    UV index (Low)
  • 62% chance of some rain62
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • No heat & humidity0
    no heat & humidity
  • Light breeze of 10 kph from the South10
    kph wind from S

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Illinois weather for Monday 22nd September 2025

Expect isolated thunderstorms in Illinois with a maximum temperature of 22°C, maximum UV of 5 (Moderate) and 3 hours of bright sunshine. There are 5-10 mm of rainfall expected with 62% chance of some rain and a light breeze of 9 kph from the south-west.

  • 22°C maximum temperature22
    °C maximum temperature
  • 21°C minimum temperature21
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 3 hours of bright sunshine3
    hours of sunshine
  • UV (maximum) index 5 (Moderate)5
    UV index (Moderate)
  • 62% chance of some rain62
    % chance of some rain
  • 5-10 mm of rainfall expected<10
    mm of rainfall expected
  • No heat & humidity0
    no heat & humidity
  • Light breeze of 9 kph from the South-West9
    kph wind from SW

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

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