May weather forecastRiverdale, IA
May
Weather in May
The last month of the spring, May, is an agreeable month in Riverdale, Iowa, with an average temperature varying between 70.3°F (21.3°C) and 53.4°F (11.9°C).Temperature
With the onset of May, Riverdale's weather sees a temperature rise, transitioning from a refreshing 59°F (15°C) in April to an agreeable 70.3°F (21.3°C). May brings an average low-temperature of 53.4°F (11.9°C) to Riverdale.Humidity
In May, the average relative humidity in Riverdale is 77%.Rainfall
May is the month with the most rainfall in Riverdale. Rain falls for 13.4 days and accumulates 1.61" (41mm) of precipitation.Snowfall
May through August are months without snowfall in Riverdale.Daylight
The average length of the day in May is 14h and 32min.On the first day of May in Riverdale, Iowa, sunrise is at 5:57 am and sunset at 8:00 pm. On the last day of the month, sunrise is at 5:30 am and sunset at 8:29 pm CDT.
Sunshine
The average sunshine in May in Riverdale, Iowa, is 8.6h.UV index
In May, the average daily maximum UV index in Riverdale, Iowa, is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum daily UV index, 5 in May, converts into the following recommendations:
Prioritize safety - The need to safeguard skin and eyes from harm is emphasized. To avoid the Sun's strongest rays, limit exposure around the mid-day period. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Riverdale, IA
- Average high temperature in May: 70.3°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (28.2°F).
- Average low temperature in May: 53.4°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 (15.4°F).
Average pressure in May
Riverdale, IA
- Average pressure in May: 29.95"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in May
Riverdale, IA
- Average wind speed in May: 9mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).
Average humidity in May
Riverdale, IA
- Average humidity in May: 77%
The months with the highest relative humidity are January and July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in May
Riverdale, IA
- Average rainfall in May: 1.61"
The wettest month (with the highest rainfall) is May (1.61").
The driest month (with the least rainfall) is December (0.35").
Average rainfall days in May
Riverdale, IA
- Average rainfall days in May: 13.4 days
The month with the highest number of rainy days is May (13.4 days).
The month with the least rainy days is January (3.2 days).
Average snowfall in May
Riverdale, IA
- Average snowfall in May: 0"
The month with the highest snowfall is January (1.26").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in May
Riverdale, IA
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is January (7.2 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in May /
Average sunshine in May
Riverdale, IA
- Average daylight in May: 14h and 30min
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 12min).
- Average sunshine in May: 8h and 36min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in May
Riverdale, IA
- Average sunshine days in May: 14.6 days
The month with the most sunshine days is December (22.4 days).
The month with the least sunshine days is June (14.4 days).
Average UV index in May
Riverdale, IA
- Average UV index in May: 5
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in May
Riverdale, IA
- Average cloud cover in May: 43
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 30).
Average visibility in May
Riverdale, IA
- Average visibility in May: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





