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
With the onset of May, Grafton's average high-temperature sees a rise, moving from April's cool 54.3°F (12.4°C) to a comfortable 66.6°F (19.2°C). The average temperature during May nights dips to a fresh 50.4°F (10.2°C).Humidity
In Grafton, the average relative humidity in May is 74%.Rainfall
In May, the rain falls for 17.2 days. Throughout May, 3.07" (78mm) of precipitation is accumulated. Throughout the year, there are 134.3 rainfall days, and 25.08" (637mm) of precipitation is accumulated.Snowfall
Months with snowfall are January through May, October through December. May is the last month it regularly snows. During 0.3 snowfall days, in May, Grafton aggregates 0.47" (12mm) of snow. In Grafton, Iowa, during the entire year, snow falls for 57 days and aggregates up to 22.83" (580mm) of snow.Daylight
In Grafton, the average length of the day in May is 14h and 43min.On the first day of the month, sunrise is at 6:04 am and sunset at 8:14 pm. On the last day of May, sunrise is at 5:34 am and sunset at 8:45 pm CDT.
Sunshine
In Grafton, the average sunshine in May is 8.4h.UV index
In Grafton, the average daily maximum UV index in May is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.Note: In May, the maximum UV index of 5 suggests this advice:
Prioritize safety - Recommendations to avert sunburn are shared. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. Tightly woven clothing, when worn loosely, shields effectively against the Sun. Take heed! Reflection from the snow can almost amplify the Sun's UV radiation by double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in May?
What is the average humidity in May?
How many days does it rain in May?
What is the last month it snows?
How many hours of daylight does Grafton have in May?
When are sunrise and sunset in May?
How many hours of sunshine does Grafton have in May?
What is the UV index intensity in May?
Average temperature in May
Grafton, IA
- Average high temperature in May: 66.6°F
The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is January (21.6°F).
- Average low temperature in May: 50.4°F
The month with the highest average low temperature is July (62.6°F).
The coldest month (with the lowest average low temperature) is January (9°F).
Average pressure in May
Grafton, IA
- Average pressure in May: 29.93"Hg
The months with the highest atmospheric pressure are January and February (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in May
Grafton, IA
- Average wind speed in May: 9.4mph
The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest months (with the lowest average wind speed) are July and August (7.4mph).
Average humidity in May
Grafton, IA
- Average humidity in May: 74%
The month with the highest relative humidity is January (90%).
The months with the lowest relative humidity are April and October (72%).
Average rainfall in May
Grafton, IA
- Average rainfall in May: 3.07"
The wettest month (with the highest rainfall) is June (4.13").
The driest month (with the least rainfall) is January (0.94").
Average rainfall days in May
Grafton, IA
- Average rainfall days in May: 17.2 days
The month with the highest number of rainy days is June (18.4 days).
The month with the least rainy days is February (2.9 days).
Average snowfall in May
Grafton, IA
- Average snowfall in May: 0.47"
The month with the highest snowfall is February (5.94").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in May
Grafton, IA
- Average snowfall days in May: 0.3 days
The month with the highest number of snowfall days is January (13.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Grafton, 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 0min).
- Average sunshine in May: 8h and 2min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).
Average sunshine days in May
Grafton, IA
- Average sunshine days in May: 11.7 days
The month with the most sunshine days is October (18.1 days).
The month with the least sunshine days is June (9.1 days).
Average UV index in May
Grafton, IA
- 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, February, November and December (UV index 1).
Average cloud cover in May
Grafton, IA
- Average cloud cover in May: 44
The month with the most cloud cover is January (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in May
Grafton, IA
- Average visibility in May: 6mi
The months with the highest visibility are March, April, May, June, September, October and November (6mi).
The months with the lowest visibility are January, February, July, August and December (5mi).
Grafton, Iowa, USA
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