Contents
- Weather in May
- Frequently asked questions
- Average temperature in May
- Average pressure in May
- Average wind speed in May
- Average humidity in May
- Average rainfall in May
- Average rainfall days in May
- Average snowfall in May
- Average snowfall days in May
- Average daylight in May
- Average sunshine in May
- Average sunshine days in May
- Average UV index in May
- Average cloud cover in May
- Average visibility in May
Weather in May
Temperature
The transition from April to May brings a temperature rise, with average high-temperatures increasing from a fresh 54.3°F (12.4°C) to an enjoyable 65.8°F (18.8°C). During the month of May, an average temperature of 48.9°F (9.4°C) is noted during the nights.Humidity
The average relative humidity in May is 81%.Rainfall
In Castalia, during May, the rain falls for 17.3 days and regularly aggregates up to 3.78" (96mm) of precipitation. Throughout the year, in Castalia, there are 131 rainfall days, and 27.91" (709mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. May is the last month it regularly snows in Castalia. During 0.3 snowfall days, in May, Castalia aggregates 0.12" (3mm) of snow. Throughout the year, in Castalia, Iowa, there are 52.3 snowfall days, and 21.26" (540mm) of snow is accumulated.Daylight
In May, the average length of the day in Castalia is 14h and 41min.On the first day of May in Castalia, sunrise is at 5:58 am and sunset at 8:08 pm. On the last day of the month, sunrise is at 5:29 am and sunset at 8:39 pm CDT.
Sunshine
In May, the average sunshine in Castalia is 8.1h.UV index
In Castalia, the average daily maximum UV index in May is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum daily UV index of 5 during May translates into the following directions:
Be vigilant - A duty to shield skin and eyes from injury exists. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear. Take heed! Reflection from the snow can almost amplify the Sun's UV radiation by double.
Frequently asked questions
What are the temperatures in Castalia in May?
What is the average humidity in May in Castalia?
How much does it rain in Castalia in May?
What is the last month it snows in Castalia?
How many hours of daylight does Castalia have in May?
When are sunrise and sunset in May in Castalia?
How many hours of sunshine does Castalia have in May?
How high is the UV index in May in Castalia?
Average temperature in May
Castalia, IA
- Average high temperature in May: 65.8°F
The warmest month (with the highest average high temperature) is July (79°F).
The month with the lowest average high temperature is January (22.5°F).
- Average low temperature in May: 48.9°F
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (9.9°F).
Average pressure in May
Castalia, IA
- Average pressure in May: 29.94"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in May
Castalia, IA
- Average wind speed in May: 9mph
The windiest month (with the highest average wind speed) is April (10.5mph).
The calmest months (with the lowest average wind speed) are July and August (7mph).
Average humidity in May
Castalia, IA
- Average humidity in May: 81%
The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is October (75%).
Average rainfall in May
Castalia, IA
- Average rainfall in May: 3.78"
The wettest month (with the highest rainfall) is June (4.33").
The driest month (with the least rainfall) is January (0.98").
Average rainfall days in May
Castalia, IA
- Average rainfall days in May: 17.3 days
The month with the highest number of rainy days is June (17.7 days).
The month with the least rainy days is February (3.8 days).
Average snowfall in May
Castalia, IA
- Average snowfall in May: 0.12"
The month with the highest snowfall is February (5.16").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in May
Castalia, IA
- Average snowfall days in May: 0.3 days
The month with the highest number of snowfall days is January (13.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Castalia, IA
- Average daylight in May: 14h and 4min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in May: 8h and 1min
The month with the most sunshine is August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).
Average sunshine days in May
Castalia, IA
- Average sunshine days in May: 12.3 days
The month with the most sunshine days is September (17 days).
The month with the least sunshine days is June (10.5 days).
Average UV index in May
Castalia, IA
- Average UV index in May: 5
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in May
Castalia, IA
- Average cloud cover in May: 45
The month with the most cloud cover is January (Cloud cover 64).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in May
Castalia, IA
- Average visibility in May: 6mi
The months with the highest visibility are March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February and July (5mi).
Castalia, Iowa, USA
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