Illinois weather live forecast

Today's maximum temperature in Illinois is expected to be 26°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 Monday 18th August 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 Sunday 17th August 2025

Expect isolated thunderstorms in Illinois with a maximum temperature of 26°C, low levels of heat & humidity, maximum UV of 4 (Moderate) and 8 hours of bright sunshine. There are 10-20 mm of rainfall expected with 22% chance of some rain and a light breeze of 9 kph from the north-east.

  • 26°C maximum temperature26
    °C maximum temperature
  • 23°C minimum temperature23
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 8 hours of bright sunshine8
    hours of sunshine
  • UV (maximum) index 4 (Moderate)4
    UV index (Moderate)
  • 22% chance of some rain22
    % chance of some rain
  • 10-20 mm of rainfall expected<20
    mm of rainfall expected
  • Low heat & humidityL
    low heat & humidity
  • Light breeze of 9 kph from the North-East9
    kph wind from NE

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Illinois weather for Monday 18th August 2025

Expect isolated thunderstorms in Illinois with a maximum temperature of 29°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 33% chance of some rain and a light breeze of 10 kph from the south-east.

  • 29°C maximum temperature29
    °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)
  • 33% chance of some rain33
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Light breeze of 10 kph from the South-East10
    kph wind from SE

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Illinois weather for Tuesday 19th August 2025

Expect isolated thunderstorms in 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 2-5 mm of rainfall expected with 38% chance of some rain and a light breeze of 10 kph from the north.

  • 29°C maximum temperature29
    °C maximum temperature
  • 24°C minimum temperature24
    °C minimum temperature
  • Isolated thunderstorms
    isolated thunderstorms
  • 5 hours of bright sunshine5
    hours of sunshine
  • UV (maximum) index 6 (High)6
    UV index (High)
  • 38% chance of some rain38
    % chance of some rain
  • 2-5 mm of rainfall expected<5
    mm of rainfall expected
  • Moderate heat & humidityM
    moderate heat & humidity
  • Light breeze of 10 kph from the North10
    kph wind from N

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Illinois weather for Wednesday 20th August 2025

Expect mostly cloudy with light rain in Illinois with a maximum temperature of 24°C, maximum UV of 7 (High) and 5 hours of bright sunshine. There are 0-2 mm of rainfall expected with 22% chance of some rain and a gentle breeze of 16 kph from the north.

  • 24°C maximum temperature24
    °C maximum temperature
  • 21°C minimum temperature21
    °C minimum temperature
  • Mostly cloudy with light rain
    mostly cloudy with light rain
  • 5 hours of bright sunshine5
    hours of sunshine
  • UV (maximum) index 7 (High)7
    UV index (High)
  • 22% chance of some rain22
    % chance of some rain
  • 0-2 mm of rainfall expected<2
    mm of rainfall expected
  • 24°C wind chill24
    °C wind chill
  • Gentle breeze of 16 kph from the North16
    kph wind from N

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Illinois weather for Thursday 21st August 2025

Expect scattered clouds in Illinois with a maximum temperature of 24°C, maximum UV of 8 (Very High) and 10 hours of bright sunshine. There are 0 mm of rainfall expected and a light breeze of 10 kph from the north-east.

  • 24°C maximum temperature24
    °C maximum temperature
  • 21°C minimum temperature21
    °C minimum temperature
  • Scattered clouds
    scattered clouds
  • 10 hours of bright sunshine10
    hours of sunshine
  • UV (maximum) index 8 (Very High)8
    UV index (Very High)
  • 0 mm of rainfall expected0
    mm of rainfall expected
  • 24°C wind chill24
    °C wind chill
  • Light breeze of 10 kph from the North-East10
    kph wind from NE

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

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