May weather forecastJefferson, IA
May
Weather in May
The last month of the spring, May, is an agreeable month in Jefferson, Iowa, with an average temperature fluctuating between 69.4°F (20.8°C) and 53.1°F (11.7°C).Temperature
Jefferson's weather shows a temperature rise with the arrival of May, moving from a moderate 58.5°F (14.7°C) in April to a pleasant 69.4°F (20.8°C). Jefferson, in May, experiences an average temperature of 53.1°F (11.7°C) at night.Humidity
In May, the average relative humidity is 74%.Rainfall
May is the month with the most rainfall. Rain falls for 16.2 days and accumulates 4.06" (103mm) of precipitation.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, Jefferson aggregates 0.12" (3mm) of snow. In Jefferson, during the entire year, snow falls for 38.1 days and aggregates up to 15.31" (389mm) of snow.Daylight
In Jefferson, the average length of the day in May is 14h and 35min.On the first day of the month, sunrise is at 6:12 am and sunset at 8:16 pm. On the last day of May, in Jefferson, sunrise is at 5:44 am and sunset at 8:46 pm CDT.
Sunshine
In Jefferson, the average sunshine in May is 8.6h.UV index
In May, the average daily maximum UV index is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the average person.Note: During May, 5 as the daily maximum UV index converts into the following advice:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Be aware! The intensity of the Sun's UV radiation can be amplified nearly twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Jefferson, IA
- Average high temperature in May: 69.4°F
The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (26.8°F).
- Average low temperature in May: 53.1°F
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (13.5°F).
Average pressure in May
Jefferson, IA
- Average pressure in May: 29.93"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in May
Jefferson, IA
- Average wind speed in May: 9.1mph
The windiest month (with the highest average wind speed) is April (10.7mph).
The calmest months (with the lowest average wind speed) are July and August (7.1mph).
Average humidity in May
Jefferson, IA
- Average humidity in May: 74%
The month with the highest relative humidity is January (84%).
The month with the lowest relative humidity is October (69%).
Average rainfall in May
Jefferson, IA
- Average rainfall in May: 4.06"
The wettest month (with the highest rainfall) is May (4.06").
The driest month (with the least rainfall) is January (0.87").
Average rainfall days in May
Jefferson, IA
- Average rainfall days in May: 16.2 days
The month with the highest number of rainy days is June (17.3 days).
The month with the least rainy days is February (3.4 days).
Average snowfall in May
Jefferson, IA
- Average snowfall in May: 0.12"
The month with the highest snowfall is January (4.29").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in May
Jefferson, IA
- Average snowfall days in May: 0.3 days
The month with the highest number of snowfall days is January (9.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Jefferson, IA
- Average daylight in May: 14h and 36min
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 36min
The month with the most sunshine is July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in May
Jefferson, IA
- Average sunshine days in May: 13.3 days
The month with the most sunshine days is November (19.4 days).
The month with the least sunshine days is June (11.1 days).
Average UV index in May
Jefferson, 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, October, November and December (UV index 2).
Average cloud cover in May
Jefferson, IA
- Average cloud cover in May: 42
The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are July and September (Cloud cover 30).
Average visibility in May
Jefferson, IA
- Average visibility in May: 6mi
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
