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United StatesThe weather in September in Washington
It's warm in September in Washington with an average temperature of 26°C. Temperatures this month range from a low of 20°C to a high of 30°C. At night, you can expect temperatures between 11°C and 18°C.
Looking for sun? September isn’t a good month to be in Washington. The temperature is nice, but there’s too much chance of rain.
Average temperatures and precipitation
This chart shows the average daily maximum and minimum temperatures (in degrees Celsius) and precipitation (in millimeters) in September for Washington, New Jersey. A low precipitation value usually indicates little to no rainfall on that day in recent years, while a higher value suggests more frequent rainfall.
Temperature records
With 35°C in 2015, Washington reached the highest temperature in September over the past 10 years. The lowest daytime temperature in this month was 14°C in 2018. The extreme nighttime temperatures ranged from a lowest recorded value of 1°C to a highest value of 24°C.
Rainfall amount
In September, there is an average of 104 mm of precipitation, spread over 13 days. The wind speed is around 3 Bft, mostly coming from the South.
Daily weather in September for Washington
Click on any day in September to get detailed info about the usual weather on that day in Washington. Check out the historical temperatures and precipitation over the past 10 years on this day.
September weather comparison
| Washington | New York | |
|---|---|---|
| Average temperature | 26°C | 27°C |
| Max. temperature | 30°C | 31°C |
| Min. temperature | 11°C | -5°C |
| Total precipitation | 104 mm | 57 mm |
| Rainy days | 13 days | 9 days |
Start of September
The month of September starts in Washington with hot temps, averaging around 28°C during the day and nights around 17°C.
Mid September
By mid-September, daytime temps drop to around 26°C, with nights around 15°C. There’s a chance of some showers during this time, but plenty of dry and sunny days too.
End of September
By the end of September, the average daytime temperature in Washington is around 24°C, while nighttime temps are about 13°C. Expect regular precipitation, but if you’re lucky, you’ll also get some dry and sunny days.
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UV index
The UV index is a maximum of 7 this month. That's a moderate to high value on the intensity scale of 1 to 11. Unprotected skin can burn within 15-25 minutes.
Check out the climate of Washington for all months and discover the best travel time
Temperature charts
These charts show the average temperatures in September in Washington, New Jersey. The temperatures are shown in degrees Celsius and are calculated based on data from the past 10 years.
Daily Temperature in September in Washington
Temperature in September in Washington over the years
Precipitation charts
These charts show the average amount of precipitation in September in Washington, New Jersey. Precipitation is always measured as water, even when it falls as snow or hail The amount of precipitation is displayed in millimeters, while snowfall is shown in centimeters.
Daily Precipitation in September in Washington
Total precipitation in September in Washington over the years
Daily UV index in September in Washington
This chart shows the average daily UV index in September in Washington, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Weather experiences in September in Washington
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Average weather in Washington by month
Click on a month below to see detailed weather info for Washington. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.