Chicago
Illinois, USA
Long-term weather forecast
Long-term weather forecast

August weather forecast and climate
Chicago, IL

An aerial view of the city of Chicago in Illinois, on the shores of Lake Michigan, with a superb view of the sandy beach of Oak Street
An aerial view of the city of Chicago in Illinois, on the shores of Lake Michigan, with a superb view of the sandy beach of Oak Street
August is the wettest month in Chicago and registers 4.9" (124.5mm) of precipitation. The sun shines for an average of 13.5 hours daily amid nine days with clear skies. Though August has calm winds, Chicago is prone to rainstorms, which sometimes register more than an inch at a time.
The average temperatures are in the 63°F (17.2°C) to 82°F (27.8°C) zone - days are over 70°F (21.1°C) most of the time but rarely touch 90°F (32.2°C); nights seldom drop below 50°F (10°C).
August sees a large number of tourists visit Chicago, next only to New York, as the city has plenty of attractions and is one of the safest in the United States regarding the weather hazards!

What is the temperature in August in Chicago?

In August, the average high-temperature is 82°F (27.8°C), and the average low-temperature is 66.2°F (19°C). In August, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), that represents influence of the relative humidity to air temperaure, is appraised at 86.7°F (30.4°C).

What is the average humidity in August in Chicago?

In Chicago, the average relative humidity in August is 70.7%.

How many days does it rain in August in Chicago?

In August, in Chicago, Illinois, the rain falls for 9 days. Throughout August, 4" (101.3mm) of precipitation is accumulated.

When it does not snow in Chicago?

May through September are months without snowfall in Chicago.

What month is the ocean warmest in Chicago?

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

How warm is the water in August in Chicago?

In Chicago, in August, the average water temperature is 73.9°F (23.3°C). Depending on a person's sensitivity to cold, with regards to sunshine, wind, and air temperature, a quick swim in 73.9°F (23.3°C) water may be enjoyable.

How many hours of daylight does Chicago have in August?

The average length of the day in August is 13.8h.

How many hours of sunshine does Chicago have in August?

The average sunshine in August in Chicago, Illinois, is 9.1h.

What is the UV index intensity in August in Chicago?

In Chicago, the average daily maximum UV index in August is 8. A UV Index reading of 8 to 10 represents a very high health threat from unprotected exposure to the UV radiation.
Average temperature in August - Chicago, IL
  • Average high temperature in August: 27.8°C

The warmest month (with the highest average high temperature) is July (29°C).
The month with the lowest average high temperature is January (-0.3°C).

  • Average low temperature in August: 19°C

The month with the highest average low temperature is July (19.7°C).
The coldest month (with the lowest average low temperature) is January (-7.7°C).

Average humidity in August - Chicago, IL
  • Average humidity in August: 70.7%

The month with the highest relative humidity is December (75.5%).
The month with the lowest relative humidity is May (64.1%).

Average rainfall in August - Chicago, IL
  • Average rainfall in August: 101.3mm

The wettest month (with the highest rainfall) is May (104.9mm).
The driest month (with the lowest rainfall) is February (49.3mm).

Average rainfall days in August - Chicago, IL
  • Average rainfall days in August: 9 days

The month with the highest number of rainy days is May (11.4 days).
The month with the lowest number of rainy days is September (8.2 days).

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

The month with the highest snowfall is January (292.1mm).
Months with the lowest snowfall are May, June, July, August and September (0mm).

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 (8.1 days).
Months with the lowest number of snowfall days are May, June, July, August and September (0 days).

Average sea temperature in August - Chicago, IL
  • Average sea temperature in August: 23.3°C

The best month for swimming (with the highest average sea temperature) is August (23.3°C).
The coldest month (with the lowest average sea temperature) is February (2.7°C).

Average daylight in August / Average sunshine in August - Chicago, IL
  • Average daylight in August: 13.8h

The month with the longest days is June (Average daylight: 15.2h).
The month with shortest days is December (Average daylight: 9.2h).

  • Average sunshine in August: 9.1h

The month with most sunshine is June (Average sunshine: 10.4h).
The month with least sunshine is December (Average sunshine: 3.4h).

Average UV index in August - Chicago, IL
  • Average UV index in August: 8

Months with the highest UV index are June and July (UV index 9).
Months with the lowest UV index are January and December (UV index 1).