Chicago weather in August 2025

Expect 28°C daytime maximum temperatures in the shade with on average 9 hours of sunshine per day in Chicago in August. Check more long-term weather averages for Chicago in August before you book your next holiday to Illinois in 2025/2026.

  • 28°C maximum daytime temperature in August in Chicago28
    28°C max day temperature
  • 9 hours of sunshine per day
  • 9 days with some rainfall in August in Chicago9
    9 days with some rainfall
  • 16°C minimum night-time temperature in August in Chicago16
    16°C min night temperature
  • 14 hours of daylight per day in August in Chicago14
    14 hours of daylight per day
  • Moderate heat & humidity in August in ChicagoM
    Moderate heat & humidity
  • 97 mm monthly rainfall in August in Chicago97
    97 mm of monthly rainfall
  • UV (maximum) index 8 (Very High) in August in Chicago8
    8 (Very High) UV index
  • 21°C sea temperature in August in Chicago21
    21°C sea temperature

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The August weather guide for Illinois (Chicago) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

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

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More about the USA

How hot is it in Chicago in August?

Daytime temperatures usually reach 28°C in Chicago in August with moderate heat and humidity, falling to 16°C at night.

How sunny is it in Chicago in August?

There are normally 9 hours of bright sunshine each day in Chicago in August - that's 67% of daylight hours.

How warm is the sea around Chicago in August?

The average sea temperature around Chicago in August is 21°C.

Does it rain in Chicago in August?

There are usually 9 days with some rain in Chicago in August and the average monthly rainfall is 97mm.

Chicago August sunrise & sunset times

Browse the sunrise and sunset times for Chicago in August 2025. Select a month to view Chicago sunrise and sunset times for the next 12 months.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Friday, 1st August 2025 04:45 19:08
Saturday, 16th August 2025 05:00 18:49
Sunday, 31st August 2025 05:16 18:25

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