Contents
- Weather in May
- Frequently asked questions
- Average temperature in May
- Average pressure in May
- Average wind speed in May
- Average humidity in May
- Average rainfall in May
- Average rainfall days in May
- Average snowfall in May
- Average snowfall days in May
- Average daylight in May
- Average sunshine in May
- Average sunshine days in May
- Average UV index in May
- Average cloud cover in May
- Average visibility in May
Weather in May
Temperature
The beginning of May signals a minor rise in the average high-temperature, moving from a refreshing 55.9°F (13.3°C) in April to an enjoyable 64.6°F (18.1°C). In the month of May, the temperature generally rests at an average low of 44.1°F (6.7°C).Humidity
The average relative humidity in May in Mercer Island is 75%.Rainfall
In May, in Mercer Island, the rain falls for 10.1 days. Throughout May, 0.79" (20mm) of precipitation is accumulated. In Mercer Island, during the entire year, the rain falls for 119.1 days and collects up to 11.97" (304mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
In May, the average length of the day is 15h and 10min.On the first day of the month, sunrise is at 5:50 am and sunset at 8:21 pm. On the last day of May, in Mercer Island, sunrise is at 5:15 am and sunset at 8:58 pm PDT.
Sunshine
In May, the average sunshine in Mercer Island is 9.2h.UV index
In May, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from unprotected exposure to Sun's UV rays for average individuals.Note: A daily maximum UV index of 4 in May translates into the following instructions:
Act with care - The suggestion to avoid sunburn is emphasized. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in May in Mercer Island?
What is the average humidity in May in Mercer Island?
How much does it rain in Mercer Island in May?
When it does not snow in Mercer Island?
What is the average length of the day in May in Mercer Island?
When is the sunrise / sunset in May in Mercer Island?
How many hours of sunshine does Mercer Island have in May?
What is the UV index intensity in May in Mercer Island?
Average temperature in May
Mercer Island, WA
- Average high temperature in May: 64.6°F
The warmest month (with the highest average high temperature) is August (76.6°F).
The month with the lowest average high temperature is December (42.8°F).
- Average low temperature in May: 44.1°F
The month with the highest average low temperature is August (53.4°F).
The coldest month (with the lowest average low temperature) is February (34.5°F).
Average pressure in May
Mercer Island, WA
- Average pressure in May: 30.02"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed in May
Mercer Island, WA
- Average wind speed in May: 3.9mph
The windiest month (with the highest average wind speed) is March (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.4mph).
Average humidity in May
Mercer Island, WA
- Average humidity in May: 75%
The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is July (69%).
Average rainfall in May
Mercer Island, WA
- Average rainfall in May: 0.79"
The wettest month (with the highest rainfall) is December (2.01").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in May
Mercer Island, WA
- Average rainfall days in May: 10.1 days
The month with the highest number of rainy days is March (13.7 days).
The month with the least rainy days is August (4.1 days).
Average snowfall in May
Mercer Island, WA
- Average snowfall in May: 0"
The month with the highest snowfall is February (1.77").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in May
Mercer Island, WA
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is February (3 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
Mercer Island, WA
- Average daylight in May: 15h and 1min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in May: 9h and 1min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 12min).
Average sunshine days in May
Mercer Island, WA
- Average sunshine days in May: 18.5 days
The month with the most sunshine days is August (24.9 days).
The month with the least sunshine days is February (13.8 days).
Average UV index in May
Mercer Island, 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, November and December (UV index 2).
Average cloud cover in May
Mercer Island, WA
- Average cloud cover in May: 42
The month with the most cloud cover is December (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in May
Mercer Island, WA
- Average visibility in May: 6mi
The months with the highest visibility are May, June, July, August and September (6mi).
The months with the lowest visibility are January, February, March, April, October, November and December (5mi).
Mercer Island, Washington, USA
Weather forecast for your location
2. Allow the app to use your location