May weather forecastRainier, OR
May
Weather in May
The last month of the spring, May, is a comfortable month in Rainier, Oregon, with temperature in the range of an average low of 40.8°F (4.9°C) and an average high of 64.8°F (18.2°C).Temperature
May's arrival sees a mild rise in the average high-temperature, transitioning from April's refreshing 55.9°F (13.3°C) to an enjoyable 64.8°F (18.2°C). The significant decline in Rainier's temperature, from day to night, averages of 40.8°F (4.9°C) in May.Humidity
The average relative humidity in May is 78%.Rainfall
In May, the rain falls for 13.9 days. Throughout May, 1.61" (41mm) of precipitation is accumulated. Throughout the year, there are 175.5 rainfall days, and 25.83" (656mm) of precipitation is accumulated.Snowfall
In Rainier, snow does not fall in April through October.Daylight
The average length of the day in May in Rainier is 14h and 59min.On the first day of the month, sunrise is at 5:56 am and sunset at 8:20 pm. On the last day of May, sunrise is at 5:24 am and sunset at 8:55 pm PDT.
Sunshine
In Rainier, the average sunshine in May is 7.9h.UV index
In May, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the average person.Note: A maximum daily UV index of 4 during May morphs into the following directions:
Ensure safety - Recommendations to avert sunburn are presented. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. 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
Rainier, OR
- Average high temperature in May: 64.8°F
The warmest month (with the highest average high temperature) is August (77.9°F).
The month with the lowest average high temperature is December (42.3°F).
- Average low temperature in May: 40.8°F
The month with the highest average low temperature is August (49.8°F).
The coldest month (with the lowest average low temperature) is December (32.7°F).
Average pressure in May
Rainier, OR
- Average pressure in May: 30.04"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).
Average wind speed in May
Rainier, OR
- Average wind speed in May: 4.2mph
The windiest month (with the highest average wind speed) is January (4.8mph).
The calmest month (with the lowest average wind speed) is September (3.9mph).
Average humidity in May
Rainier, OR
- Average humidity in May: 78%
The months with the highest relative humidity are January, February, November and December (88%).
The month with the lowest relative humidity is July (72%).
Average rainfall in May
Rainier, OR
- Average rainfall in May: 1.61"
The wettest month (with the highest rainfall) is January (3.9").
The driest month (with the least rainfall) is August (0.39").
Average rainfall days in May
Rainier, OR
- Average rainfall days in May: 13.9 days
The month with the highest number of rainy days is March (20.3 days).
The month with the least rainy days is July (6.1 days).
Average snowfall in May
Rainier, OR
- Average snowfall in May: 0"
The month with the highest snowfall is January (1.26").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in May
Rainier, OR
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is February (2.2 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).
Average daylight in May /
Average sunshine in May
Rainier, OR
- Average daylight in May: 15h and 0min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in May: 7h and 54min
The month with the most sunshine is August (Average sunshine: 10h and 24min).
The months with the least sunshine are January, February and December (Average sunshine: 3h and 30min).
Average sunshine days in May
Rainier, OR
- Average sunshine days in May: 15.3 days
The month with the most sunshine days is July (22 days).
The month with the least sunshine days is March (8.9 days).
Average UV index in May
Rainier, OR
- Average UV index in May: 4
The months with the highest UV index are June and July (UV index 5).
The month with the lowest UV index is November (UV index 1).
Average cloud cover in May
Rainier, OR
- Average cloud cover in May: 55
The months with the most cloud cover are February and March (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 36).
Average visibility in May
Rainier, OR
- Average visibility in May: 4mi
The month with the highest visibility is August (5mi).
The months with the lowest visibility are January, February, March, April, May, June, July, September, October, November and December (4mi).





