Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The onset of September aligns with a soft reduction in the average high-temperature, gently falling from 82°F (27.8°C) in August to a still warm 75.7°F (24.3°C). In Washington, the expected average low-temperature for September is a fresh 54.9°F (12.7°C).Humidity
In September, the average relative humidity in Washington is 79%.Rainfall
In Washington, in September, during 11.7 rainfall days, 1.02" (26mm) of precipitation is typically accumulated. Throughout the year, in Washington, there are 143 rainfall days, and 14.8" (376mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:49 am and sunset at 7:52 pm. On the last day of September, sunrise is at 7:17 am and sunset at 7:04 pm EDT.
Sunshine
The average sunshine in September is 8.5h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for ordinary individuals.Note: The maximum UV index, 4 during September, leads to the following recommendations:
Take precautions - Protection against sun damage is advised. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Washington in September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
Does it snow in September?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Washington have in September?
What is the UV index intensity in September?
Average temperature in September
Washington, PA
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (83.3°F).
The month with the lowest average high temperature is January (33.6°F).
- Average low temperature in September: 54.9°F
The month with the highest average low temperature is July (61.9°F).
The coldest month (with the lowest average low temperature) is January (20.8°F).
Average pressure in September
Washington, PA
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in September
Washington, PA
- Average wind speed in September: 5mph
The windiest month (with the highest average wind speed) is January (7.8mph).
The calmest month (with the lowest average wind speed) is August (4.5mph).
Average humidity in September
Washington, PA
- Average humidity in September: 79%
The month with the highest relative humidity is February (85%).
The months with the lowest relative humidity are April, July and August (77%).
Average rainfall in September
Washington, PA
- Average rainfall in September: 1.02"
The wettest month (with the highest rainfall) is July (1.65").
The driest months (with the least rainfall) are January and November (0.94").
Average rainfall days in September
Washington, PA
- Average rainfall days in September: 11.7 days
The month with the highest number of rainy days is May (17.2 days).
The month with the least rainy days is February (7.3 days).
Average snowfall in September
Washington, PA
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.26").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Washington, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Washington, PA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 8h and 3min
The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).
Average sunshine days in September
Washington, PA
- Average sunshine days in September: 15.9 days
The month with the most sunshine days is November (19.1 days).
The month with the least sunshine days is May (11.8 days).
Average UV index in September
Washington, PA
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Washington, PA
- Average cloud cover in September: 38
The month with the most cloud cover is January (Cloud cover 68).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in September
Washington, PA
- Average visibility in September: 5mi
The months with the highest visibility are April and November (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October and December (5mi).
Washington, Pennsylvania, USA
Weather forecast for your location
2. Allow the app to use your location