The highest day temperature in May 2026 was 105°F. The lowest night temperature was 43°F. The average values for day and night temperatures during May were 76.8°F и 58.7°F respectivly.

The average sea surface temperature in May 2026 for Washington was 69.2°F. The maximum and minimum values were 64.2°F and 78.2°F respectively.

Most of the days in May are sunny but you can also expect cloudy and gloomy days.

Precipitation total in May for Washington is 2.7 in. It makes may one of the most rainy months of the year.

The average wind speed in May is 7.3 mph.

We are using day length and cloud cover information for each day of the month to calculate averages for this chart. Average sunny hours for Washington in May is 8.2 hours.