August weather forecast
Chicago, IL

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The city of Chicago in Illinois on the shores of Lake Michigan, with a superb view of the sandy beach of Oak Street
The city of Chicago in Illinois on the shores of Lake Michigan, with a superb view of the sandy beach of Oak Street

Weather in August

August maintains the summer momentum in Chicago, providing locals and visitors with ample sunshine and heat. The weather conditions are similar to July, maintaining high temperatures and favorable conditions for outdoor activities or sightseeing. However, toward the end of the month, there is a subtle drop in temperatures indicating an impending change. Prepare to bid farewell to the peak summer season and embrace the approach of autumn as the city transitions in the late August days.

Temperature

In Chicago, August is identified by the highest average temperatures, reaching a peak of 77.5°F (25.3°C) and a low of 67.6°F (19.8°C).

Humidity

In Chicago, the average relative humidity in August is 76%.

Rainfall

In August, the rain falls for 17.3 days. Throughout August, 4.06" (103mm) of precipitation is accumulated. Throughout the year, there are 160.2 rainfall days, and 36.97" (939mm) of precipitation is accumulated.

Snowfall

In Chicago, snow does not fall in June through October.

Ocean temperature

The month with the warmest seawater is August, with an average ocean temperature of 73.9°F (23.3°C).
Note: Factor in your tolerance to cold, the sunshine, the wind, and the air's warmth, and a swim in 73.9°F (23.3°C) might be tempting. It is interesting to note that Olympians compete in 77°F (25°C) to 82.4°F (28°C) water temperatures.

Daylight

In Chicago, the average length of the day in August is 13h and 49min.
On the first day of August, sunrise is at 5:45 am and sunset at 8:08 pm. On the last day of the month, sunrise is at 6:16 am and sunset at 7:25 pm CDT.

Sunshine

July and August, with an average of 10.6h of sunshine, are months with the most sunshine.

UV index

July and August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for average individuals.
Note: In August, the maximum UV index of 6 suggests this advice:
Act on precautions and pay attention to sun safety recommendations. Avoidance of sunburn is obligatory. It's important to stay in the shade and limit exposure to the sun from 10 a.m. to 4 p.m., when UV radiation is most intense, although remember that shade structures may not provide full sun protection. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun. Take warning! Reflective sand and water surfaces intensify the Sun's UV rays.
Updated: Aug 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What month is the hottest?

August, recording an average high temperature of 77.5°F (25.3°C) and a low temperature of 67.6°F (19.8°C), is Chicago's warmest month.

What is the temperature in August?

The high-temperature, in August, in Chicago, records 77.5°F (25.3°C), while the low-temperature is 67.6°F (19.8°C).

What is the average humidity in August?

In August, the average relative humidity is 76%.

How much does it rain in August?

In Chicago, in August, during 17.3 rainfall days, 4.06" (103mm) of precipitation is typically accumulated.

When it does not snow?

June through October are months without snowfall.

What month is the ocean warmest?

With an average ocean temperature of 73.9°F (23.3°C), August is the month with the warmest seawater.

What is the water temperature in August?

In August, the average ocean temperature is 73.9°F (23.3°C). A person's cold intolerance, with sunshine, wind, and air temperature, are essential factors for enjoying swimming in 73.9°F (23.3°C) water.

How many hours of daylight does Chicago have in August?

In August, the average day length is 13h and 49min.

What time are sunrise and sunset in August?

On the first day of August, sunrise is at 5:45 am and sunset at 8:08 pm. On the last day of the month, sunrise is at 6:16 am and sunset at 7:25 pm CDT.

What is the month with the most sunshine?

July and August, with an average of 10.6h of sunshine, are months with the most sunshine.

How many hours of sunshine does Chicago have in August?

In Chicago, the average sunshine duration in August is 10.6h.

What is the month with the highest UV index?

July and August, with an average maximum UV index of 6, are months with the highest UV index.

How high is the UV index in August?

The average daily maximum UV index in August is 6. A UV Index reading of 6 to 7 represents a high health threat from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
Chicago, IL

Average temperature in August - Chicago, IL
  • Average high temperature in August: 77.5°F

The warmest month (with the highest average high temperature) is August (77.5°F).
The month with the lowest average high temperature is January (29.7°F).

  • Average low temperature in August: 67.6°F

The month with the highest average low temperature is July (67.8°F).
The coldest month (with the lowest average low temperature) is January (20.7°F).

Average pressure in August
Chicago, IL

Average pressure in August - Chicago, IL
  • Average pressure in August: 29.98"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in August
Chicago, IL

Average wind speed in August - Chicago, IL
  • Average wind speed in August: 7.8mph

The windiest month (with the highest average wind speed) is January (12.5mph).
The calmest month (with the lowest average wind speed) is July (7.7mph).

Average humidity in August
Chicago, IL

Average humidity in August - Chicago, IL
  • Average humidity in August: 76%

The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is October (73%).

Average rainfall in August
Chicago, IL

Average rainfall in August - Chicago, IL
  • Average rainfall in August: 4.06"

The wettest month (with the highest rainfall) is June (4.88").
The driest month (with the least rainfall) is December (1.65").

Average rainfall days in August
Chicago, IL

Average rainfall days in August - Chicago, IL
  • Average rainfall days in August: 17.3 days

The month with the highest number of rainy days is July (18.5 days).
The month with the least rainy days is February (5.5 days).

Average snowfall in August
Chicago, IL

Average snowfall in August - Chicago, IL
  • Average snowfall in August: 0"

The month with the highest snowfall is February (3.54").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in August
Chicago, IL

Average snowfall days in August - Chicago, IL
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (10.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average sea temperature in August
Chicago, IL

Average sea temperature in August - Chicago, IL
  • Average sea temperature in August: 73.9°F

The best month for swimming (with the highest average sea temperature) is August (73.9°F).
The coldest month (with the lowest average sea temperature) is February (36.9°F).

Average daylight in August /
Average sunshine in August
Chicago, IL

Average daylight in August / Average sunshine in August - Chicago, IL
  • Average daylight in August: 13h and 5min

The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).

  • Average sunshine in August: 10h and 4min

The months with the most sunshine are July and August (Average sunshine: 10h and 36min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

Average sunshine days in August
Chicago, IL

Average sunshine days in August - Chicago, IL
  • Average sunshine days in August: 9.8 days

The month with the most sunshine days is December (15.5 days).
The month with the least sunshine days is July (9.3 days).

Average UV index in August
Chicago, IL

Average UV index in August - Chicago, IL
  • Average UV index in August: 6

The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January and December (UV index 1).

Average cloud cover in August
Chicago, IL

Average cloud cover in August - Chicago, IL
  • Average cloud cover in August: 27

The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are July and August (Cloud cover 27).

Average visibility in August
Chicago, IL

Average visibility in August - Chicago, IL
  • Average visibility in August: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Chicago, Illinois, USA

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