May weather forecastRiverside, WA
May
Weather in May
The last month of the spring, May, is a comfortable month in Riverside, Washington, with an average temperature varying between 66°F (18.9°C) and 42.4°F (5.8°C).Temperature
Riverside's May weather brings a rise in high-temperatures, moving from a fresh 54.3°F (12.4°C) in April to an enjoyable 66°F (18.9°C). With a notable difference from peak temperatures, an average of 42.4°F (5.8°C) marks the nights in Riverside in May.Humidity
The average relative humidity in May is 56%.Rainfall
In Riverside, in May, during 8.6 rainfall days, 0.91" (23mm) of precipitation is typically accumulated. Throughout the year, in Riverside, there are 90.2 rainfall days, and 7.56" (192mm) of precipitation is accumulated.Snowfall
In Riverside, snow does not fall in May through October.Daylight
The average length of the day in May is 15h and 16min.On the first day of the month, sunrise is at 5:36 am and sunset at 8:13 pm. On the last day of May, sunrise is at 5:00 am and sunset at 8:51 pm PDT.
Sunshine
In May, the average sunshine in Riverside is 11.2h.UV index
The average daily maximum UV index in May is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.Note: The UV index of 4 during May leads to these advisories:
Act with care - The need to guard against sun damage is communicated. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Riverside, WA
- Average high temperature in May: 66°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is December (30.4°F).
- Average low temperature in May: 42.4°F
The month with the highest average low temperature is August (55°F).
The coldest month (with the lowest average low temperature) is December (18.1°F).
Average pressure in May
Riverside, WA
- Average pressure in May: 29.95"Hg
The month with the highest atmospheric pressure is January (30.17"Hg).
The months with the lowest atmospheric pressure are June and August (29.93"Hg).
Average wind speed in May
Riverside, WA
- Average wind speed in May: 4.8mph
The windiest month (with the highest average wind speed) is April (5.1mph).
The calmest month (with the lowest average wind speed) is January (4mph).
Average humidity in May
Riverside, WA
- Average humidity in May: 56%
The month with the highest relative humidity is January (91%).
The months with the lowest relative humidity are July and August (42%).
Average rainfall in May
Riverside, WA
- Average rainfall in May: 0.91"
The wettest month (with the highest rainfall) is December (0.94").
The driest months (with the least rainfall) are July and August (0.2").
Average rainfall days in May
Riverside, WA
- Average rainfall days in May: 8.6 days
The month with the highest number of rainy days is March (11.5 days).
The month with the least rainy days is August (2.8 days).
Average snowfall in May
Riverside, WA
- Average snowfall in May: 0"
The month with the highest snowfall is January (3.39").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in May
Riverside, WA
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is December (8.4 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Riverside, WA
- Average daylight in May: 15h and 18min
The month with the longest days is June (Average daylight: 16h and 6min).
The month with the shortest days is December (Average daylight: 8h and 24min).
- Average sunshine in May: 11h and 12min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in May
Riverside, WA
- Average sunshine days in May: 21.3 days
The month with the most sunshine days is August (26.3 days).
The month with the least sunshine days is November (15.4 days).
Average UV index in May
Riverside, WA
- Average UV index in May: 4
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is November (UV index 1).
Average cloud cover in May
Riverside, WA
- Average cloud cover in May: 25
The month with the most cloud cover is January (Cloud cover 49).
The months with the least cloud cover are July and August (Cloud cover 12).
Average visibility in May
Riverside, WA
- Average visibility in May: 6mi
The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February and December (4mi).
