Washington weather in September 2025
September
Washington weather in September 2025
September
Day
22 °C
Night
9 °C
Sea
11 °C
Precipitation
43 mm
in month
Rainy days
8 days
in month
Daylight
12 hours
average
Sunshine
7 hours
average
Humidity
76 %
Day
22 °C
Night
9 °C
Sea
11 °C
Precipitation
43 mm
in month
Rainy days
8 days
in month
Daylight
12 hours
average
Sunshine
7 hours
average
Humidity
76 %
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Weather overview and FAQs
Weather overview
In Washington in September, the average air temperature ranges from 22 °C (71 °F) during the day to 9 °C (49 °F) at night. There are 8 days of rain on average, where the rainfall is 43 mm (1.70 in).
Are there good conditions to visit in Washington in September?
In Washington in September, there are ideal conditions for a vacation. There are only 8 days of rain in the whole month, so you can leave your umbrella at home. There are some people, who may feel a slight chill at 22 °C (71 °F), but others will feel perfectly fine. The temperature of 9 °C (49 °F) at night may make it better to dine inside or to put on more clothes for a dinner outside.
What is the average number of rainy days in Washington in September?
In Washington in September, we can expect 8 days to be rainy, that is, days when precipitation exceeds 2 mm (0.08 in). Converted to days of the week, this means that it will occur on an average of 2.0 days of the week, or in general - 28 % days.
What temperature can I expect during the day in Washington in September?
In Washington in September, the average daily temperatures will be 22 °C (71 °F). A comfortable temperature for most people, where it is neither too cold nor too hot, and a large number of activities can be carried out comfortably, including sunbathing by the water. Lighter clothing will be suitable - shorts, skirts, t-shirts, jackets; a light sweater and long trousers may also be useful.
What is the night temperature in September in Washington?
The average night temperature in Washington in September is 9 °C (49 °F). The nights will be cool, layers of clothes will be needed for evening and morning walks, the hotel should be equipped with heating.
Is there a dry season in September in Washington?
Yes, there is a dry season in Washington in September with just 8 days during the month being rainy.
How many hours of sun to expect in Washington in September?
There is an average length of sunshine of 7 hours per day in Washington in September.
What level of humidity is to expect in September in Washington?
In Washington in September, expect humidity around 76 %.
Is Washington rainier in September than in October?
No, September in Washington is not a rainier month than October.
How windy is it in September in Washington?
An average wind scale that can be expected in Washington in September is 3. It is rather a milder or unnoticeable wind, therefore it will not bother you during your holiday.
How long is the day (from dawn till dusk) in Washington in September?
The length of daylight in Washington in September is 12 hours.
What is the temperature trend in Washington in September?
During September in Washington, the day temperatures are decreasing - from 23 °C (74 °F) at the beginning of the month to 19 °C (66 °F) at the end of the month.
Is the weather in Washington warmer in September than in October?
Yes, in Washington in September it is warmer than in October by 6 °C (42 °F).
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