May weather forecastSaint Helens, OR
May
Weather in May
May, the last month of the spring in Saint Helens, is an enjoyable month, with an average temperature varying between 39.9°F (4.4°C) and 62.8°F (17.1°C).Temperature
May's arrival coincides with a marginal rise in the average high-temperature, moving from April's cool 54.3°F (12.4°C) to a refreshing 62.8°F (17.1°C). Saint Helens, in May, experiences a marked contrast from daytime zeniths to a steady average low-temperature of 39.9°F (4.4°C).Humidity
The average relative humidity in May is 79%.Rainfall
In May, the rain falls for 12.8 days. Throughout May, 1.26" (32mm) of precipitation is accumulated. In Saint Helens, during the entire year, the rain falls for 149 days and collects up to 19.37" (492mm) of precipitation.Snowfall
In Saint Helens, snow does not fall in May through October.Daylight
In Saint Helens, the average length of the day in May is 14h and 58min.On the first day of May, sunrise is at 5:56 am and sunset at 8:19 pm. On the last day of the month, sunrise is at 5:24 am and sunset at 8:53 pm PDT.
Sunshine
In Saint Helens, the average sunshine in May is 7.8h.UV index
In Saint Helens, the average daily maximum UV index in May is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for the average person.Note: A typical high UV index of 4 in May suggests the following recommendations:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Saint Helens, OR
- Average high temperature in May: 62.8°F
The warmest month (with the highest average high temperature) is August (76.5°F).
The month with the lowest average high temperature is December (41.9°F).
- Average low temperature in May: 39.9°F
The month with the highest average low temperature is August (47.8°F).
The coldest month (with the lowest average low temperature) is December (31.8°F).
Average pressure in May
Saint Helens, OR
- Average pressure in May: 30.03"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).
Average wind speed in May
Saint Helens, OR
- Average wind speed in May: 3.9mph
The windiest month (with the highest average wind speed) is January (5.3mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).
Average humidity in May
Saint Helens, OR
- Average humidity in May: 79%
The month with the highest relative humidity is February (88%).
The months with the lowest relative humidity are July and August (72%).
Average rainfall in May
Saint Helens, OR
- Average rainfall in May: 1.26"
The wettest month (with the highest rainfall) is January (2.64").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in May
Saint Helens, OR
- Average rainfall days in May: 12.8 days
The month with the highest number of rainy days is March (16 days).
The month with the least rainy days is July (5.9 days).
Average snowfall in May
Saint Helens, OR
- Average snowfall in May: 0"
The month with the highest snowfall is January (1.97").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in May
Saint Helens, OR
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is February (3.6 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in May /
Average sunshine in May
Saint Helens, 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 48min
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 42min).
Average sunshine days in May
Saint Helens, OR
- Average sunshine days in May: 16.8 days
The month with the most sunshine days is July (23.7 days).
The month with the least sunshine days is February (12.1 days).
Average UV index in May
Saint Helens, OR
- Average UV index in May: 4
The month with the highest UV index is July (UV index 5).
The month with the lowest UV index is November (UV index 1).
Average cloud cover in May
Saint Helens, OR
- Average cloud cover in May: 53
The month with the most cloud cover is March (Cloud cover 63).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in May
Saint Helens, OR
- Average visibility in May: 4mi
The months with the highest visibility are July and August (5mi).
The months with the lowest visibility are January, February, March, April, May, June, September, October, November and December (4mi).
