September weather forecast
Skykomish, WA

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A calm Skykomish river with clear waters, visible stones, with a view of the iconic Lewis Street Bridge, near Monroe in Washington
A calm Skykomish river with clear waters, visible stones, with a view of the iconic Lewis Street Bridge, near Monroe in Washington

Weather in September

September, the first month of the autumn in Skykomish, is still a comfortable month, with an average temperature ranging between min 40.5°F (4.7°C) and max 62.1°F (16.7°C).

Temperature

Start of September brings a slight shift in the average high-temperature, dipping a bit from August's agreeable 69.4°F (20.8°C) to a comfortable 62.1°F (16.7°C). September presents a pronounced divergence from daily peak temperatures, with the average low-temperature of 40.5°F (4.7°C).

Humidity

The average relative humidity in September is 77%.

Rainfall

In September, the rain falls for 15.1 days. Throughout September, 2.6" (66mm) of precipitation is accumulated. In Skykomish, during the entire year, the rain falls for 207.7 days and collects up to 61.81" (1570mm) of precipitation.

Snowfall

In Skykomish, snow does not fall in June through October.

Daylight

The average length of the day in September is 12h and 33min.
On the first day of the month, sunrise is at 6:25 am and sunset at 7:45 pm. On the last day of September, sunrise is at 7:04 am and sunset at 6:45 pm PDT.

Sunshine

In September, the average sunshine is 8h.

UV index

In September, the average daily maximum UV index in Skykomish is 2. A UV Index value of 2, and less, symbolizes a minimal health vulnerability from unsafe exposure to UV radiation for average individuals.
Note: The maximum UV index of 2 during September leads to these instructions:
While most individuals can withstand prolonged sun exposure, it is imperative that babies, children, and those with sensitive skin always be shielded. To avoid the Sun's strongest rays, limit exposure around the mid-day period. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Updated: Jul 19, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

Skykomish in September has an average high-temperature of 62.1°F (16.7°C) and an average low-temperature of 40.5°F (4.7°C).

What is the average humidity in September?

In Skykomish, the average relative humidity in September is 77%.

How many days does it rain in September?

In September, the rain falls for 15.1 days. Throughout September, 2.6" (66mm) of precipitation is accumulated.

When it does not snow?

June through October are months without snowfall.

How many hours of daylight does Skykomish have in September?

In September, the average day length is 12h and 33min.

What time are sunrise and sunset in September?

On the first day of September, sunrise is at 6:25 am and sunset at 7:45 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:45 pm PDT.

How many hours of sunshine does Skykomish have in September?

In September, the average sunshine duration is 8h.

How high is the UV index in September in Skykomish?

In September, the average daily maximum UV index is 2. A UV Index reading of 2, and below, represents a minimal hazard to health from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Skykomish, WA

Average temperature in September - Skykomish, WA
  • Average high temperature in September: 62.1°F

The warmest month (with the highest average high temperature) is August (69.4°F).
The month with the lowest average high temperature is December (32.9°F).

  • Average low temperature in September: 40.5°F

The month with the highest average low temperature is August (44.2°F).
The coldest month (with the lowest average low temperature) is December (22.1°F).

Average pressure in September
Skykomish, WA

Average pressure in September - Skykomish, WA
  • Average pressure in September: 29.99"Hg

The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is August (29.98"Hg).

Average wind speed in September
Skykomish, WA

Average wind speed in September - Skykomish, WA
  • Average wind speed in September: 3.4mph

The windiest month (with the highest average wind speed) is January (4.8mph).
The calmest months (with the lowest average wind speed) are August and September (3.4mph).

Average humidity in September
Skykomish, WA

Average humidity in September - Skykomish, WA
  • Average humidity in September: 77%

The month with the highest relative humidity is February (93%).
The months with the lowest relative humidity are July and August (73%).

Average rainfall in September
Skykomish, WA

Average rainfall in September - Skykomish, WA
  • Average rainfall in September: 2.6"

The wettest month (with the highest rainfall) is January (9.96").
The driest month (with the least rainfall) is July (0.94").

Average rainfall days in September
Skykomish, WA

Average rainfall days in September - Skykomish, WA
  • Average rainfall days in September: 15.1 days

The month with the highest number of rainy days is April (22.6 days).
The month with the least rainy days is August (9.9 days).

Average snowfall in September
Skykomish, WA

Average snowfall in September - Skykomish, WA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (16.26").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in September
Skykomish, WA

Average snowfall days in September - Skykomish, WA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is December (11 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Skykomish, WA

Average daylight in September / Average sunshine in September - Skykomish, WA
  • Average daylight in September: 12h and 3min

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: 8h and 0min

The month with the most sunshine is August (Average sunshine: 10h and 18min).
The months with the least sunshine are January, February and December (Average sunshine: 3h and 0min).

Average sunshine days in September
Skykomish, WA

Average sunshine days in September - Skykomish, WA
  • Average sunshine days in September: 12.5 days

The month with the most sunshine days is August (17.9 days).
The months with the least sunshine days are February and April (5.8 days).

Average UV index in September
Skykomish, WA

Average UV index in September - Skykomish, WA
  • Average UV index in September: 2

The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February and November (UV index 1).

Average cloud cover in September
Skykomish, WA

Average cloud cover in September - Skykomish, WA
  • Average cloud cover in September: 48

The month with the most cloud cover is March (Cloud cover 71).
The month with the least cloud cover is August (Cloud cover 35).

Average visibility in September
Skykomish, WA

Average visibility in September - Skykomish, WA
  • Average visibility in September: 4mi

The months with the highest visibility are July and August (5mi).
The months with the lowest visibility are January and February (3mi).

Skykomish, Washington, USA

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