Normal weather for Friday Harbor in September
It's pleasantly warm in September in Friday Harbor with an average temperature of 20°C. Temperatures this month range from a low of 18°C to a high of 23°C. At night, you can expect temperatures between 9°C and 12°C.
In September, there is an average of 24 mm of precipitation, spread over 5 days. The wind speed is around 3 Bft, mostly coming from the South.
Friday Harbor in September |
London | ||
|---|---|---|---|
 Average Temperature |
20°C | 20°C | |
 High Temp |
23°C | 22°C | |
| Low Temp |
18°C | 17°C | |
 Total Precipitation |
24 mm | 44 mm | |
| Rainy Days |
5 days | 8 days | |
Start of September
The month of September starts in Friday Harbor with warm temperatures, averaging around 23°C during the day and nights close to 12°C. There’s little chance of precipitation. The weather is mostly sunny and dry.
Since temperatures can differ between day and night, it’s a good idea to dress in layers. A T-shirt, light trousers or skirt, and a light jacket are perfect for daytime. In the evening and morning, we recommend a light coat, jumper or cardigan, and long trousers.
Mid-September
By mid-September, the average daytime temperature drops to around 20°C, with nights close to 11°C. Not much precipitation expected during this period. It’s mostly dry with sunshine.
Temperatures vary between day and night, so it’s smart to wear layers. During the day, a shirt, maybe a light cardigan, and light trousers will do. In the evening and morning, we recommend a light coat, jumper or cardigan, and long trousers.
End of September
By the end of September, the average daytime temperature in Friday Harbor will be around 19°C, with nights close to 11°C. Barely any chance of precipitation. The weather will mostly be dry with lots of sunshine.
As it gets cooler in the evening, it’s best to wear layers. During the day, a shirt, maybe a light cardigan, and light trousers will do. In the evening and morning, we recommend a warm coat, jumper or cardigan, and long trousers.
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UV index
The UV index is a maximum of 5 this month. That's a moderate value on the intensity scale of 1 to 11. Unprotected skin can burn in about 30 minutes.
Is September a good time to visit Friday Harbor?
Want nice weather? Then September is a great time to be in Friday Harbor. You’ll have pleasant temperatures and not too much rain this month.
Temperature records for Friday Harbor in September
With 31°C, Friday Harbor hit the highest temperature in the last 10 years in September 2017. The lowest daytime temperature in this month was 13°C in 2020. The extreme night temperatures ranged from a low of 4°C to a high of 17°C.
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Daily Temperature in September in Friday Harbor
This chart shows the average daily temperatures, both day and night, for each day in September in Friday Harbor, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in September in Friday Harbor
The chart below shows the average daily precipitation in September for Friday Harbor, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for September, you can expect around 5 days of rain in Friday Harbor.
Daily UV Index in September in Friday Harbor
This chart shows the average daily UV index in September in Friday Harbor, 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.
Temperature in September in Friday Harbor Over the Years
This chart shows the average temperature in September in Friday Harbor, measured in degrees Celsius, over the past years.
Total Precipitation in September in Friday Harbor Over the Years
This chart shows the average precipitation in September in Friday Harbor, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Daily climate in September for Friday Harbor
Click on a specific day in September for detailed info on the typical weather on that day in Friday Harbor. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in September in Friday Harbor
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Average Weather in Friday Harbor by Month
Click on a month below to see detailed weather info for Friday Harbor. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
Or check out the climate of Friday Harbor for all months at once
