May weather forecastWinthrop, WA

May
Weather in May
May in Winthrop ushers in truly pleasant weather, although temperatures remain moderate. The higher temperature reaches an average of 58.3°F (14.6°C) and the lower bounds at around 35.2°F (1.8°C). Amidst the changing weather, the level of rainfall in May is quite optimal with an average of 1.42" (36mm). Longer daylight hours and more sunshine bring about the expansion of the beautiful flora around the town. The end of May sees the advent of summer, leading to rising temperatures in the upcoming month of June.Temperature
Winthrop's transition into May is marked by a rise in the average high-temperature, advancing from a chilly 46°F (7.8°C) in April to a moderate 58.3°F (14.6°C). Winthrop anticipates a considerable daily temperature fluctuation in May, with low temperatures averaging a cold 35.2°F (1.8°C).Humidity
In May, the average relative humidity is 68%.Rainfall
In May, the rain falls for 14.2 days. Throughout May, 1.42" (36mm) of precipitation is accumulated. Throughout the year, there are 142.6 rainfall days, and 17.91" (455mm) of precipitation is accumulated.Snowfall
May through August are months without snowfall in Winthrop.Daylight
In May, the average length of the day is 15h and 16min.On the first day of May, sunrise is at 5:39 am and sunset at 8:15 pm. On the last day of the month, sunrise is at 5:03 am and sunset at 8:53 pm PDT.
Sunshine
In May, the average sunshine is 10.6h.UV index
The average daily maximum UV index in May is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for ordinary individuals.Note: The daily high UV index of 4 in May translates into this advice:
Take precautions - Protection against skin and eye damage is obliged. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Winthrop, WA
- Average high temperature in May: 58.3°F
The warmest month (with the highest average high temperature) is August (75.9°F).
The month with the lowest average high temperature is December (27.5°F).
- Average low temperature in May: 35.2°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 (13.5°F).
Average pressure in May
Winthrop, WA
- Average pressure in May: 29.96"Hg
The month with the highest atmospheric pressure is January (30.15"Hg).
The months with the lowest atmospheric pressure are June and August (29.95"Hg).
Average wind speed in May
Winthrop, WA
- Average wind speed in May: 4.6mph
The windiest months (with the highest average wind speed) are June and July (5mph).
The calmest months (with the lowest average wind speed) are January and December (3.6mph).
Average humidity in May
Winthrop, WA
- Average humidity in May: 68%
The month with the highest relative humidity is January (93%).
The months with the lowest relative humidity are July and August (53%).
Average rainfall in May
Winthrop, WA
- Average rainfall in May: 1.42"
The wettest month (with the highest rainfall) is December (2.48").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in May
Winthrop, WA
- Average rainfall days in May: 14.2 days
The month with the highest number of rainy days is March (17.3 days).
The month with the least rainy days is August (6.1 days).
Average snowfall in May
Winthrop, WA
- Average snowfall in May: 0"
The month with the highest snowfall is December (12.87").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in May
Winthrop, WA
- Average snowfall days in May: 0.1 days
The month with the highest number of snowfall days is December (15.3 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in May /
Average sunshine in May
Winthrop, 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: 10h and 36min
The month with the most sunshine is August (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in May
Winthrop, WA
- Average sunshine days in May: 14.2 days
The month with the most sunshine days is August (23 days).
The month with the least sunshine days is March (8.3 days).
Average UV index in May
Winthrop, WA
- Average UV index in May: 4
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February and November (UV index 1).
Average cloud cover in May
Winthrop, WA
- Average cloud cover in May: 33
The month with the most cloud cover is January (Cloud cover 55).
The month with the least cloud cover is August (Cloud cover 15).
Average visibility in May
Winthrop, WA
- Average visibility in May: 6mi
The months with the highest visibility are May, June, July, August, September and October (6mi).
The months with the lowest visibility are January and February (3mi).





