Seattle
Washington, USA
Long-term weather forecast
Long-term weather forecast

May weather forecast and Climate
Seattle, WA

Beautiful dusk skyline over the giant skyscrapers of Seattle, Washington
May is the loveliest month in Seattle as the days begin to become longer than nights. Temperatures rise to a moderately warm range of 46.4°F (8°C) to 64.4°F (18°C) and humidity drops to a tolerable 68.3% making this the best weather across the year.
Rain only falls for eleven days, and the rain gauge meters read 2.1" (53.3mm) making it easier to tour Seattle without interruptions. Packing an emergency rain jacket is necessary.
The sea warms up to a moderately lovely 53.6°F (12°C) and the eight hours of sunshine make swimming worthwhile.
  • The average high temperature in May: 18.2°C

The warmest month (with the highest average high temperature) is August (24.6°C).
The month with the lowest average high temperature is December (7.6°C).

  • The average low temperature in May: 8.5°C

The month with the highest average low temperature is August (13.3°C).
The coldest month (with the lowest average low temperature) is December (2°C).

  • The average humidity in May: 68.9%

The month with the highest relative humidity is December (80.1%).
The month with the lowest relative humidity is July (65.4%).

  • The average rainfall in May: 49.3mm

The wettest month (with the highest rainfall) is November (166.9mm).
The driest month (with the lowest rainfall) is July (17.8mm).

  • The average rainfall days in May: 12 days

The month with the highest number of rainy days is November (18.4 days).
The month with the lowest number of rainy days is August (4.8 days).

  • The average snowfall in May: 0mm

Months with the highest snowfall are February and December (43.2mm).
Months with the lowest snowfall are April, May, June, July, August, September and October (0mm).

  • The average snowfall days in May: 0 days

The month with the highest number of snowfall days is December (1.6 days).
Months with the lowest number of snowfall days are April, May, June, July, August, September and October (0 days).

  • The average daylight in May: 15h

Months with the longest days are June and July (Average daylight: 16h).
The month with shortest days is December (Average daylight: 8h).

  • The average sunshine in May: 8.2h

The month with most sunshine is July (Average sunshine: 10.1h).
The month with least sunshine is December (Average sunshine: 1.7h).

  • The average UV index in May: 6

Months with the highest UV index are June and July (UV index 7).
Months with the lowest UV index are January, November and December (UV index 1).

deutscheenglishespañolрусский中文