May weather forecast
Round Lake Heights, IL

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Weather in May

May, the last month of the spring in Round Lake Heights, is a comfortable month, with temperature in the range of an average high of 65.3°F (18.5°C) and an average low of 49.6°F (9.8°C).

Temperature

With the beginning of May, Round Lake Heights's average high-temperature sees an increase, transitioning from a cool 53.6°F (12°C) in April to an enjoyable 65.3°F (18.5°C). Round Lake Heights experiences an average temperature drop to a chilly 49.6°F (9.8°C) during May nights.

Humidity

In Round Lake Heights, the average relative humidity in May is 78%.

Rainfall

In Round Lake Heights, in May, during 17 rainfall days, 2.44" (62mm) of precipitation is typically accumulated. Throughout the year, in Round Lake Heights, Illinois, there are 142.3 rainfall days, and 21.97" (558mm) of precipitation is accumulated.

Snowfall

January through May, October through December are months with snowfall in Round Lake Heights. May is the last month it regularly snows in Round Lake Heights. During 0.2 snowfall days, in May, Round Lake Heights aggregates 0.04" (1mm) of snow. In Round Lake Heights, during the entire year, snow falls for 49.5 days and aggregates up to 13.54" (344mm) of snow.

Daylight

The average length of the day in May in Round Lake Heights is 14h and 37min.
On the first day of the month, sunrise is at 5:46 am and sunset at 7:52 pm. On the last day of May, sunrise is at 5:18 am and sunset at 8:22 pm CDT.

Sunshine

In May, the average sunshine is 8.5h.

UV index

In Round Lake Heights, the average daily maximum UV index in May is 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for average individuals.
Note: The maximum UV index of 5 during May translates into these guidelines:
Ensure safety - Sun damage prevention is strongly urged. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Foresee this! The reflection from snow can nearly double the intensity of UV radiation from the Sun.
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 Round Lake Heights?

An average high-temperature, in May, in Round Lake Heights, is 65.3°F (18.5°C) and the average low-temperature is 49.6°F (9.8°C).

What is the average humidity in May in Round Lake Heights?

In Round Lake Heights, the average relative humidity in May is 78%.

How much does it rain in Round Lake Heights in May?

In Round Lake Heights, Illinois, in May, during 17 rainfall days, 2.44" (62mm) of precipitation is typically accumulated.

What is the last month it snows in Round Lake Heights?

May is the last month it regularly snows in Round Lake Heights, Illinois. During 0.2 snowfall days, in May, Round Lake Heights aggregates 0.04" (1mm) of snow.

How many hours of daylight does Round Lake Heights have in May?

The average day length in May in Round Lake Heights, Illinois, is 14h and 37min.

When are sunrise and sunset in May in Round Lake Heights?

In May, on the first day of the month, sunrise is at 5:46 am and sunset at 7:52 pm. On the last day of the month, in Round Lake Heights, Illinois, sunrise is at 5:18 am and sunset at 8:22 pm CDT.

How long on average sun shines in May in Round Lake Heights?

In Round Lake Heights, Illinois, the average sunshine duration in May is 8.5h.

What is the UV index reading in May in Round Lake Heights?

In May, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a medium hazard to health from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in May
Round Lake Heights, IL

Average temperature in May - Round Lake Heights, IL
  • Average high temperature in May: 65.3°F

The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (27.5°F).

  • Average low temperature in May: 49.6°F

The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (16.5°F).

Average pressure in May
Round Lake Heights, IL

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

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

Average wind speed in May
Round Lake Heights, IL

Average wind speed in May - Round Lake Heights, IL
  • Average wind speed in May: 8.4mph

The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).

Average humidity in May
Round Lake Heights, IL

Average humidity in May - Round Lake Heights, IL
  • Average humidity in May: 78%

The months with the highest relative humidity are January and February (83%).
The month with the lowest relative humidity is October (74%).

Average rainfall in May
Round Lake Heights, IL

Average rainfall in May - Round Lake Heights, IL
  • Average rainfall in May: 2.44"

The wettest month (with the highest rainfall) is April (2.72").
The driest month (with the least rainfall) is December (0.98").

Average rainfall days in May
Round Lake Heights, IL

Average rainfall days in May - Round Lake Heights, IL
  • Average rainfall days in May: 17 days

The month with the highest number of rainy days is July (17.5 days).
The month with the least rainy days is February (5 days).

Average snowfall in May
Round Lake Heights, IL

Average snowfall in May - Round Lake Heights, IL
  • Average snowfall in May: 0.04"

The month with the highest snowfall is January (3.58").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in May
Round Lake Heights, IL

Average snowfall days in May - Round Lake Heights, IL
  • Average snowfall days in May: 0.2 days

The month with the highest number of snowfall days is January (13.7 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in May /
Average sunshine in May
Round Lake Heights, IL

Average daylight in May / Average sunshine in May - Round Lake Heights, 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 6min).

  • Average sunshine in May: 8h and 3min

The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).

Average sunshine days in May
Round Lake Heights, IL

Average sunshine days in May - Round Lake Heights, IL
  • Average sunshine days in May: 10.8 days

The month with the most sunshine days is November (17.1 days).
The month with the least sunshine days is May (10.8 days).

Average UV index in May
Round Lake Heights, IL

Average UV index in May - Round Lake Heights, IL
  • Average UV index in May: 5

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 May
Round Lake Heights, IL

Average cloud cover in May - Round Lake Heights, IL
  • Average cloud cover in May: 43

The month with the most cloud cover is January (Cloud cover 61).
The months with the least cloud cover are July, August and September (Cloud cover 30).

Average visibility in May
Round Lake Heights, IL

Average visibility in May - Round Lake Heights, IL
  • Average visibility in May: 6mi

The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).

Round Lake Heights, Illinois, USA

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