May weather forecast
Castleton, IL

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Weather in May

The last month of the spring, May, is an agreeable month in Castleton, Illinois, with an average temperature varying between 71.1°F (21.7°C) and 54.1°F (12.3°C).

Temperature

The onset of May brings a temperature shift, with the average high-temperature moving from a refreshing 59.7°F (15.4°C) in April to an agreeable 71.1°F (21.7°C). Throughout May, Castleton experiences a low-temperature average of 54.1°F (12.3°C).

Humidity

In Castleton, the average relative humidity in May is 78%.

Rainfall

May is the month with the most rainfall in Castleton. Rain falls for 15.2 days and accumulates 2.24" (57mm) of precipitation.

Snowfall

May through September are months without snowfall in Castleton, Illinois.

Daylight

In May, the average length of the day is 14h and 30min.
On the first day of the month, sunrise is at 5:55 am and sunset at 7:56 pm. On the last day of May, in Castleton, sunrise is at 5:28 am and sunset at 8:24 pm CDT.

Sunshine

In May, the average sunshine is 8.8h.

UV index

In Castleton, the average daily maximum UV index in May is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: In May, a regular UV index of 5 translates into these guidelines:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. 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 are May temperatures in Castleton?

In May, in Castleton, the average high-temperature is 71.1°F (21.7°C), and the average low-temperature is 54.1°F (12.3°C).

What is the average humidity in May in Castleton?

In Castleton, Illinois, the average relative humidity in May is 78%.

What is the wettest month in Castleton?

The month with the most rainfall in Castleton is May, when the rain falls for 15.2 days and typically aggregates up to 2.24" (57mm) of precipitation.

How many days does it rain in May in Castleton?

In May, in Castleton, the rain falls for 15.2 days. Throughout May, 2.24" (57mm) of precipitation is accumulated.

When it does not snow in Castleton?

In Castleton, snow does not fall in May through September.

Does it snow in Castleton in May?

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

How many hours of daylight does Castleton have in May?

In Castleton, Illinois, the average day length in May is 14h and 30min.

What time are sunrise and sunset in May in Castleton?

In May, on the first day of the month, sunrise is at 5:55 am and sunset at 7:56 pm. On the last day of the month, in Castleton, sunrise is at 5:28 am and sunset at 8:24 pm CDT.

How long on average sun shines in May in Castleton?

In Castleton, the average sunshine duration in May is 8.8h.

How high is the UV index in May in Castleton?

In May, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a medium health risk from exposure to Sun's UV rays.
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
Castleton, IL

Average temperature in May - Castleton, IL
  • Average high temperature in May: 71.1°F

The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (29.7°F).

  • Average low temperature in May: 54.1°F

The month with the highest average low temperature is July (64.8°F).
The coldest month (with the lowest average low temperature) is January (17.8°F).

Average pressure in May
Castleton, IL

Average pressure in May - Castleton, IL
  • Average pressure in May: 29.95"Hg

The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in May
Castleton, IL

Average wind speed in May - Castleton, IL
  • Average wind speed in May: 9mph

The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).

Average humidity in May
Castleton, IL

Average humidity in May - Castleton, IL
  • Average humidity in May: 78%

The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).

Average rainfall in May
Castleton, IL

Average rainfall in May - Castleton, IL
  • Average rainfall in May: 2.24"

The wettest month (with the highest rainfall) is May (2.24").
The driest month (with the least rainfall) is January (0.59").

Average rainfall days in May
Castleton, IL

Average rainfall days in May - Castleton, IL
  • Average rainfall days in May: 15.2 days

The month with the highest number of rainy days is May (15.2 days).
The months with the least rainy days are January and February (4.2 days).

Average snowfall in May
Castleton, IL

Average snowfall in May - Castleton, IL
  • Average snowfall in May: 0"

The month with the highest snowfall is January (1.81").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in May
Castleton, IL

Average snowfall days in May - Castleton, IL
  • Average snowfall days in May: 0 days

The month with the highest number of snowfall days is January (8.6 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
Castleton, IL

Average daylight in May / Average sunshine in May - Castleton, IL
  • Average daylight in May: 14h and 3min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in May: 8h and 5min

The months with the most sunshine are June and July (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).

Average sunshine days in May
Castleton, IL

Average sunshine days in May - Castleton, IL
  • Average sunshine days in May: 12.8 days

The month with the most sunshine days is November (21.3 days).
The month with the least sunshine days is May (12.8 days).

Average UV index in May
Castleton, IL

Average UV index in May - Castleton, IL
  • Average UV index in May: 5

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

Average cloud cover in May
Castleton, IL

Average cloud cover in May - Castleton, IL
  • Average cloud cover in May: 41

The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 30).

Average visibility in May
Castleton, IL

Average visibility in May - Castleton, IL
  • Average visibility in May: 6mi

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

Castleton, Illinois, USA

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