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

May 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
May is a warm spring month in Chicago with pleasant temperatures in the average range of 48°F (8.9°C) to 70°F (21.1°C). Days are routinely above 50°F (10°C), and some even register 80°F (26.7°C), while nights invariably tend to be above 40°F (4.4°C).
The sunlight lasts for 262 hours as the days stretch beyond 14 hours. The skies are mostly cloudy due to the persistent wet conditions with 3.7" (94mm) of rainfall in May.
While the flowers blossom in the lovely weather, spring is a season of surprises, and it is a good idea to carry raincoats or jackets to shield from sudden outbursts of rain.

What is the temperature in May in Chicago?

The average high-temperature, in May, in Chicago, Illinois, is 70.2°F (21.2°C), while the average low-temperature is 51.6°F (10.9°C).

What is the least humid month in Chicago?

The least humid month is May, with an average relative humidity of 64.1%.

What is the average humidity in May in Chicago?

In Chicago, Illinois, the average relative humidity in May is 64.1%.

How much does it rain in Chicago in May?

In Chicago, Illinois, in May, during 11.4 rainfall days, 4.1" (104.9mm) of precipitation is typically accumulated.

What is the wettest month in Chicago?

The month with the most rainfall in Chicago is May when the rain falls for 11.4 days and typically aggregates up to 4.1" (104.9mm) of precipitation.

Does it snow in Chicago in May?

In May, it doesn't snow. April is the latest month when it typically snows.

When it does not snow in Chicago?

May through September are months without snowfall in Chicago.

What is the ocean temperature in May in Chicago?

In Chicago, the average seawater temperature in May is 45°F (7.2°C). Swimming in 45°F (7.2°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

How many hours of daylight does Chicago have in May?

In May, the average length of the day in Chicago, Illinois, is 14.6h.

How many hours of sunshine does Chicago have in May?

The average sunshine in May in Chicago is 9.1h.

What is the UV index reading in May in Chicago?

The average daily maximum UV index in May in Chicago is 7. A UV Index value of 6 to 7 symbolizes a high health risk from the exposure to the Sun's UV radiation.
Average temperature in May - Chicago, IL
  • Average high temperature in May: 21.2°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 May: 10.9°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 May - Chicago, IL
  • Average humidity in May: 64.1%

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 May - Chicago, IL
  • Average rainfall in May: 104.9mm

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 May - Chicago, IL
  • Average rainfall days in May: 11.4 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 May - Chicago, IL
  • Average snowfall in May: 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 May - Chicago, IL
  • Average snowfall days in May: 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 May - Chicago, IL
  • Average sea temperature in May: 7.2°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 May / Average sunshine in May - Chicago, IL
  • Average daylight in May: 14.6h

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 May: 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 May - Chicago, IL
  • Average UV index in May: 7

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).