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
Keystone's May weather brings a rise in high-temperatures, moving from a mild 57.7°F (14.3°C) in April to a pleasant 68.7°F (20.4°C). During May, Keystone records an average temperature of 52.2°F (11.2°C) at night.Humidity
In Keystone, the average relative humidity in May is 78%.Rainfall
The month with the most rainfall in Keystone is May, when the rain falls for 18.1 days and typically aggregates up to 4.61" (117mm) of precipitation.Snowfall
Months with snowfall in Keystone are January through May, October through December. May is the last month it regularly snows. During 0.2 snowfall days, in May, Keystone aggregates 0.12" (3mm) of snow. Throughout the year, there are 39 snowfall days, and 16.69" (424mm) of snow is accumulated.Daylight
In May, the average length of the day in Keystone is 14h and 35min.On the first day of the month, sunrise is at 6:03 am and sunset at 8:08 pm. On the last day of May, sunrise is at 5:35 am and sunset at 8:37 pm CDT.
Sunshine
In Keystone, the average sunshine in May is 8.5h.UV index
The average daily maximum UV index in May in Keystone is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for average individuals.Note: A typical high UV index of 5 in May suggests the following recommendations:
Ensure safety - Sun damage prevention is strongly urged. Avoiding the Sun's peak radiation during midday hours is essential for health and safety. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses. Take warning! The intensity of the Sun's UV radiation can be nearly amplified twice due to snow reflection.
Frequently asked questions
What are the temperatures in Keystone in May?
What is the average humidity in May in Keystone?
What is the rainiest month in Keystone?
How much does it rain in Keystone in May?
What is the last month it snows in Keystone?
What is the average length of the day in May in Keystone?
When are sunrise and sunset in May in Keystone?
How many hours of sunshine does Keystone have in May?
How high is the UV index in May in Keystone?
Average temperature in May
Keystone, IA
- Average high temperature in May: 68.7°F
The warmest month (with the highest average high temperature) is July (80.8°F).
The month with the lowest average high temperature is January (25.9°F).
- Average low temperature in May: 52.2°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 (13.5°F).
Average pressure in May
Keystone, IA
- Average pressure in May: 29.94"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.89"Hg).
Average wind speed in May
Keystone, IA
- Average wind speed in May: 9.2mph
The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest month (with the lowest average wind speed) is August (7mph).
Average humidity in May
Keystone, IA
- Average humidity in May: 78%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is October (72%).
Average rainfall in May
Keystone, IA
- Average rainfall in May: 4.61"
The wettest month (with the highest rainfall) is May (4.61").
The driest month (with the least rainfall) is January (1.18").
Average rainfall days in May
Keystone, IA
- Average rainfall days in May: 18.1 days
The month with the highest number of rainy days is June (19.3 days).
The month with the least rainy days is January (4.5 days).
Average snowfall in May
Keystone, IA
- Average snowfall in May: 0.12"
The month with the highest snowfall is January (5.24").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in May
Keystone, IA
- Average snowfall days in May: 0.2 days
The month with the highest number of snowfall days is February (10.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Keystone, IA
- 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 3min
The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in May
Keystone, IA
- Average sunshine days in May: 10.6 days
The month with the most sunshine days is October (19.2 days).
The month with the least sunshine days is June (8.4 days).
Average UV index in May
Keystone, IA
- Average UV index in May: 5
The month with the highest UV index is June (UV index 6).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover in May
Keystone, IA
- Average cloud cover in May: 43
The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is September (Cloud cover 30).
Average visibility in May
Keystone, IA
- Average visibility in May: 6mi
The months with the highest visibility are February, March, April, May, June, August, September, October, November and December (6mi).
The months with the lowest visibility are January and July (5mi).
Keystone, Iowa, USA
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