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 sea temperature 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
August's transformation into September witnesses an average high-temperature of a still refreshing 62.8°F (17.1°C), noting a minor change from the preceding month. Coupeville records an average low-temperature of 53.4°F (11.9°C) throughout the month of September.Humidity
The average relative humidity in September is 79%.Rainfall
In September, the rain falls for 11.9 days. Throughout September, 1.57" (40mm) of precipitation is accumulated. Throughout the year, there are 183.8 rainfall days, and 24.45" (621mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall.Ocean temperature
August and September, with an average ocean temperature of 53.1°F (11.7°C), are months with the warmest seawater in Coupeville.Note: Swimming in 53.1°F (11.7°C) is considered life-threatening. Even a few minutes in 55.4°F (13°C) water is uncomfortable, and swimming below 50°F (10°C) may cause total loss of breathing control and cold shock, depending on a person's physique.
Daylight
The average length of the day in September is 12h and 34min.On the first day of September, sunrise is at 6:29 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:09 am and sunset at 6:51 pm PDT.
Sunshine
In Coupeville, the average sunshine in September is 9.5h.UV index
In Coupeville, Washington, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for ordinary individuals.Note: In September, the maximum UV index of 4 suggests this advice:
Exercise prevention - Protecting skin and eyes from harm is required. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
What are the months with the warmest ocean?
What is the ocean temperature in September?
How many hours of daylight does Coupeville have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Coupeville, WA
- Average high temperature in September: 62.8°F
The warmest month (with the highest average high temperature) is July (66.2°F).
The month with the lowest average high temperature is December (43.7°F).
- Average low temperature in September: 53.4°F
The month with the highest average low temperature is August (55.9°F).
The coldest month (with the lowest average low temperature) is February (37.9°F).
Average pressure in September
Coupeville, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.08"Hg).
The months with the lowest atmospheric pressure are March, August and September (30.01"Hg).
Average wind speed in September
Coupeville, WA
- Average wind speed in September: 4.7mph
The windiest month (with the highest average wind speed) is November (8.3mph).
The calmest month (with the lowest average wind speed) is August (4.3mph).
Average humidity in September
Coupeville, WA
- Average humidity in September: 79%
The months with the highest relative humidity are January, February and March (81%).
The month with the lowest relative humidity is July (76%).
Average rainfall in September
Coupeville, WA
- Average rainfall in September: 1.57"
The wettest month (with the highest rainfall) is November (3.46").
The driest month (with the least rainfall) is July (0.47").
Average rainfall days in September
Coupeville, WA
- Average rainfall days in September: 11.9 days
The month with the highest number of rainy days is March (21.1 days).
The month with the least rainy days is August (7.5 days).
Average snowfall in September
Coupeville, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (3.27").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Coupeville, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (3.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in September
Coupeville, WA
- Average sea temperature in September: 52.9°F
The best month for swimming (with the highest average sea temperature) is August (53°F).
The coldest month (with the lowest average sea temperature) is February (45°F).
Average daylight in September /
Average sunshine in September
Coupeville, WA
- Average daylight in September: 12h and 4min
The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 24min).
- Average sunshine in September: 9h and 3min
The month with the most sunshine is August (Average sunshine: 11h and 0min).
The month with the least sunshine is December (Average sunshine: 4h and 36min).
Average sunshine days in September
Coupeville, WA
- Average sunshine days in September: 16.2 days
The month with the most sunshine days is August (21.7 days).
The month with the least sunshine days is March (7.5 days).
Average UV index in September
Coupeville, WA
- Average UV index in September: 4
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Coupeville, WA
- Average cloud cover in September: 30
The month with the most cloud cover is December (Cloud cover 52).
The month with the least cloud cover is August (Cloud cover 22).
Average visibility in September
Coupeville, 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).
Coupeville, Washington, USA
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