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 results in a decrease in the average high-temperature, receding from a hot 87.8°F (31°C) in August to a warm 77.2°F (25.1°C). In September, Plymouth's temperature tends to fall to an average low of 57.4°F (14.1°C) during the night.Humidity
In Plymouth, the average relative humidity in September is 44%.Rainfall
In Plymouth, in September, it is raining for 5.6 days, with typically 0.31" (8mm) of accumulated precipitation. In Plymouth, during the entire year, the rain falls for 106.1 days and collects up to 7.76" (197mm) of precipitation.Snowfall
Months with snowfall are January through March, September, November and December. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. In Plymouth, during the entire year, snow falls for 10.3 days and aggregates up to 6.02" (153mm) of snow.Daylight
The average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:19 am and sunset at 7:34 pm. On the last day of September, sunrise is at 6:55 am and sunset at 6:38 pm PDT.
Sunshine
The average sunshine in September is 10.7h.UV index
In Plymouth, Washington, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: In September, a daily maximum UV index of 4 leads to the following instructions:
Adopt protective measures - Suggestions to resist sunburn are offered. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades. Take warning! The intensity of the Sun's UV radiation can be nearly amplified twice due to snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Plymouth in September?
What is the average humidity in September?
How many days does it rain in September?
When does it start to snow?
How many hours of daylight does Plymouth have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Plymouth, WA
- Average high temperature in September: 77.2°F
The warmest month (with the highest average high temperature) is July (89.1°F).
The month with the lowest average high temperature is December (38.7°F).
- Average low temperature in September: 57.4°F
The month with the highest average low temperature is August (64.2°F).
The coldest month (with the lowest average low temperature) is December (28.6°F).
Average pressure in September
Plymouth, WA
- Average pressure in September: 29.96"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).
Average wind speed in September
Plymouth, WA
- Average wind speed in September: 7.2mph
The windiest month (with the highest average wind speed) is April (9.3mph).
The calmest month (with the lowest average wind speed) is December (6.2mph).
Average humidity in September
Plymouth, WA
- Average humidity in September: 44%
The month with the highest relative humidity is January (79%).
The months with the lowest relative humidity are July and August (36%).
Average rainfall in September
Plymouth, WA
- Average rainfall in September: 0.31"
The wettest month (with the highest rainfall) is March (1.02").
The driest month (with the least rainfall) is July (0.16").
Average rainfall days in September
Plymouth, WA
- Average rainfall days in September: 5.6 days
The month with the highest number of rainy days is March (13.1 days).
The month with the least rainy days is July (3.8 days).
Average snowfall in September
Plymouth, WA
- Average snowfall in September: 0.04"
The month with the highest snowfall is February (2.83").
The months with the least snowfall are April, May, June, July, August and October (0").
Average snowfall days in September
Plymouth, WA
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is December (3.2 days).
The months with the least snowfall days are April, May, June, July, August and October (0 days).
Average daylight in September /
Average sunshine in September
Plymouth, WA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 10h and 4min
The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are January and December (Average sunshine: 5h and 24min).
Average sunshine days in September
Plymouth, WA
- Average sunshine days in September: 22.6 days
The month with the most sunshine days is July (25.3 days).
The month with the least sunshine days is February (14 days).
Average UV index in September
Plymouth, WA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Plymouth, WA
- Average cloud cover in September: 16
The months with the most cloud cover are January and December (Cloud cover 44).
The month with the least cloud cover is July (Cloud cover 9).
Average visibility in September
Plymouth, WA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Plymouth, Washington, USA
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