The highest day temperature in September 2024 was 90°F. The lowest night temperature was 54°F. The average values for day and night temperatures during September were 80.1°F и 66.3°F respectivly.

The average sea surface temperature in September 2024 for Washington was 78.0°F. The maximum and minimum values were 72.4°F and 83.0°F respectively.

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

Precipitation total in September for Washington is 2.3 in. It makes september one of the least rainy months of the year.

The average wind speed in September is 6.4 mph. It makes September one of the most windless months of the year for Washington.

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 September is 7.4 hours.