May weather forecast
Lake Forest, IL

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Weather in May

The last month of the spring, May, is a comfortable month in Lake Forest, Illinois, with an average temperature varying between 49.6°F (9.8°C) and 61.2°F (16.2°C).

Temperature

May sees a rise in the average high-temperature, climbing from a cool 50.9°F (10.5°C) in April to a comfortable 61.2°F (16.2°C). Throughout May, Lake Forest witnesses a nighttime temperature average of 49.6°F (9.8°C).

Humidity

The average relative humidity in May in Lake Forest is 79%.

Rainfall

The months with the most rainfall are May and June, with an average 3.82" (97mm) of precipitation.

Snowfall

May through September are months without snowfall in Lake Forest, Illinois.

Daylight

In Lake Forest, the average length of the day in May is 14h and 37min.
On the first day of the month, sunrise is at 5:45 am and sunset at 7:51 pm. On the last day of May, in Lake Forest, sunrise is at 5:17 am and sunset at 8:20 pm CDT.

Sunshine

The average sunshine in May is 8.9h.

UV index

The average daily maximum UV index in May in Lake Forest is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.
Note: An average maximum UV index of 4 in May leads to these recommendations:
Put precautions into practice - Ensuring skin and eye safety is a necessity. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. In the presence of strong sunlight, it's crucial to wear sunglasses that ward off UVA and UVB rays.
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average May temperature in Lake Forest?

In May, in Lake Forest, the average high-temperature is 61.2°F (16.2°C), and the average low-temperature is 49.6°F (9.8°C).

What is the average humidity in May in Lake Forest?

In Lake Forest, the average relative humidity in May is 79%.

What is the rainiest month in Lake Forest?

The wettest months are May and June, with an average 3.82" (97mm) of rainfall.

How much does it rain in Lake Forest in May?

In Lake Forest, Illinois, in May, it is raining for 17.7 days, with typically 3.82" (97mm) of accumulated precipitation.

When it does not snow in Lake Forest?

May through September are months without snowfall in Lake Forest.

Does it snow in Lake Forest in May?

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

What is the average length of the day in May in Lake Forest?

In May, the average day length is 14h and 37min.

When is the sunrise / sunset in May in Lake Forest?

On the first day of May in Lake Forest, Illinois, sunrise is at 5:45 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 5:17 am and sunset at 8:20 pm CDT.

How many hours of sunshine does Lake Forest have in May?

In Lake Forest, Illinois, the average sunshine duration in May is 8.9h.

How high is the UV index in May in Lake Forest?

The average daily maximum UV index in May is 4. A UV Index reading of 3 to 5 represents a moderate vulnerability 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 May
Lake Forest, IL

Average temperature in May - Lake Forest, IL
  • Average high temperature in May: 61.2°F

The warmest month (with the highest average high temperature) is July (77.7°F).
The month with the lowest average high temperature is January (28.6°F).

  • Average low temperature in May: 49.6°F

The months with the highest average low temperature are July and August (66.7°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).

Average pressure in May
Lake Forest, IL

Average pressure in May - Lake Forest, IL
  • Average pressure in May: 29.96"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

Average wind speed in May
Lake Forest, IL

Average wind speed in May - Lake Forest, IL
  • Average wind speed in May: 9.1mph

The windiest month (with the highest average wind speed) is January (11.9mph).
The calmest month (with the lowest average wind speed) is August (7.4mph).

Average humidity in May
Lake Forest, IL

Average humidity in May - Lake Forest, IL
  • Average humidity in May: 79%

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

Average rainfall in May
Lake Forest, IL

Average rainfall in May - Lake Forest, IL
  • Average rainfall in May: 3.82"

The wettest months (with the highest rainfall) are May and June (3.82").
The driest month (with the least rainfall) is December (1.3").

Average rainfall days in May
Lake Forest, IL

Average rainfall days in May - Lake Forest, IL
  • Average rainfall days in May: 17.7 days

The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is February (5.9 days).

Average snowfall in May
Lake Forest, IL

Average snowfall in May - Lake Forest, IL
  • Average snowfall in May: 0"

The month with the highest snowfall is January (4.13").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in May
Lake Forest, IL

Average snowfall days in May - Lake Forest, IL
  • Average snowfall days in May: 0 days

The month with the highest number of snowfall days is January (11.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

Average daylight in May /
Average sunshine in May
Lake Forest, IL

Average daylight in May / Average sunshine in May - Lake Forest, IL
  • Average daylight in May: 14h and 4min

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 May: 8h and 5min

The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).

Average sunshine days in May
Lake Forest, IL

Average sunshine days in May - Lake Forest, IL
  • Average sunshine days in May: 11.2 days

The month with the most sunshine days is December (15.3 days).
The month with the least sunshine days is April (10.8 days).

Average UV index in May
Lake Forest, IL

Average UV index in May - Lake Forest, IL
  • Average UV index in May: 4

The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in May
Lake Forest, IL

Average cloud cover in May - Lake Forest, IL
  • Average cloud cover in May: 41

The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July and August (Cloud cover 27).

Average visibility in May
Lake Forest, IL

Average visibility in May - Lake Forest, IL
  • Average visibility in May: 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).

Lake Forest, Illinois, USA

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