September weather forecastPoulsbo, WA

September
Weather in September
Poulsbo witnesses distinct weather changes in September as the city begins its shift from summer to autumn. While there's a drop in temperature, rainfall levels show an upward trend. Daylight and sunshine hours also diminish, indicating less sun-filled days compared to August. Sea temperatures remain relatively high, encouraging water-related activities. Transitioning to October, the city prepares for more consistent autumn weather.Temperature
The advent of September in Poulsbo, Washington, brings a subtle shift in temperature, with the average high moving from a warm 73.6°F (23.1°C) in August to a comfortable 67.3°F (19.6°C). During the month of September, Poulsbo's nighttime temperature lowers to an average of 51.8°F (11°C).Humidity
The average relative humidity in September is 76%.Rainfall
In Poulsbo, in September, during 11.3 rainfall days, 1.22" (31mm) of precipitation is typically accumulated. Throughout the year, in Poulsbo, there are 179.1 rainfall days, and 24.57" (624mm) of precipitation is accumulated.Snowfall
In Poulsbo, snow does not fall in May through October.Ocean temperature
August and September, with an average ocean temperature of 53.2°F (11.8°C), are months with the warmest seawater in Poulsbo.Note: You can swim in 53.2°F (11.8°C) below 50°F (10°C) with proper thermal wear; failing that, the cold shock and respiratory challenges are nearly certain. A short span at 55.4°F (13°C) without it is tough.
Daylight
In Poulsbo, Washington, the average length of the day in September is 12h and 33min.On the first day of the month, sunrise is at 6:30 am and sunset at 7:50 pm. On the last day of September, sunrise is at 7:09 am and sunset at 6:51 pm PDT.
Sunshine
In Poulsbo, the average sunshine in September is 9.6h.UV index
In Poulsbo, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. To cut down UV radiation exposure by about half, sport a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Poulsbo, WA
- Average high temperature in September: 67.3°F
The warmest month (with the highest average high temperature) is August (73.6°F).
The month with the lowest average high temperature is December (43.2°F).
- Average low temperature in September: 51.8°F
The month with the highest average low temperature is August (54.9°F).
The coldest month (with the lowest average low temperature) is February (36.1°F).
Average pressure in September
Poulsbo, WA
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.09"Hg).
The months with the lowest atmospheric pressure are March, August and September (30.01"Hg).
Average wind speed in September
Poulsbo, WA
- Average wind speed in September: 4mph
The windiest months (with the highest average wind speed) are March and November (5.8mph).
The calmest month (with the lowest average wind speed) is August (3.4mph).
Average humidity in September
Poulsbo, WA
- Average humidity in September: 76%
The months with the highest relative humidity are January and December (85%).
The month with the lowest relative humidity is July (71%).
Average rainfall in September
Poulsbo, WA
- Average rainfall in September: 1.22"
The wettest month (with the highest rainfall) is January (3.74").
The driest month (with the least rainfall) is July (0.43").
Average rainfall days in September
Poulsbo, WA
- Average rainfall days in September: 11.3 days
The month with the highest number of rainy days is March (20.9 days).
The month with the least rainy days is August (6.3 days).
Average snowfall in September
Poulsbo, WA
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.09").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Poulsbo, WA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in September
Poulsbo, WA
- Average sea temperature in September: 53.1°F
The best month for swimming (with the highest average sea temperature) is August (53.2°F).
The coldest month (with the lowest average sea temperature) is February (45.3°F).
Average daylight in September /
Average sunshine in September
Poulsbo, WA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in September: 9h and 36min
The month with the most sunshine is August (Average sunshine: 10h and 54min).
The months with the least sunshine are January and December (Average sunshine: 4h and 48min).
Average sunshine days in September
Poulsbo, WA
- Average sunshine days in September: 16.9 days
The month with the most sunshine days is August (21.7 days).
The month with the least sunshine days is March (7.8 days).
Average UV index in September
Poulsbo, WA
- Average UV index in September: 4
The months with the highest UV index are June and 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
Poulsbo, WA
- Average cloud cover in September: 30
The months with the most cloud cover are January and December (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 23).
Average visibility in September
Poulsbo, WA
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).





