September weather forecast
Snoqualmie, WA

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Weather in September

The first month of the autumn, September, is still a refreshing month in Snoqualmie, Washington, with an average temperature ranging between max 67.8°F (19.9°C) and min 46°F (7.8°C).

Temperature

September signifies a gentle decline in Snoqualmie's average high-temperature, easing from a moderately hot 74.8°F (23.8°C) in August to an enjoyable 67.8°F (19.9°C). In Snoqualmie, the nighttime temperature registers a significant drop from daytime peaks to an average of 46°F (7.8°C) in September.

Humidity

In Snoqualmie, the average relative humidity in September is 75%.

Rainfall

In Snoqualmie, during September, the rain falls for 12.6 days and regularly aggregates up to 1.89" (48mm) of precipitation. Throughout the year, in Snoqualmie, there are 184.9 rainfall days, and 39.96" (1015mm) of precipitation is accumulated.

Snowfall

May through October are months without snowfall in Snoqualmie, Washington.

Daylight

The average length of the day in September is 12h and 32min.
On the first day of September, sunrise is at 6:27 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 6:47 pm PDT.

Sunshine

In Snoqualmie, Washington, the average sunshine in September is 8.9h.

UV index

In September, the average daily maximum UV index is 3. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for average individuals.
Note: A maximum daily UV index of 3 during September morphs into the following directions:
Act with care - The need to guard against sun damage is communicated. UV radiation from the Sun is most dangerous during midday; take precautions and seek shade. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in September in Snoqualmie?

In September, the average high-temperature and low-temperature in Snoqualmie are 67.8°F (19.9°C) and 46°F (7.8°C) respectively.

What is the average humidity in September in Snoqualmie?

The average relative humidity in September in Snoqualmie, Washington, is 75%.

How much does it rain in Snoqualmie in September?

In Snoqualmie, Washington, in September, it is raining for 12.6 days, with typically 1.89" (48mm) of accumulated precipitation.

When it does not snow in Snoqualmie?

May through October are months without snowfall in Snoqualmie, Washington.

What is the average length of the day in September in Snoqualmie?

In Snoqualmie, Washington, the average day length in September is 12h and 32min.

What time are sunrise and sunset in September in Snoqualmie?

On the first day of September in Snoqualmie, Washington, sunrise is at 6:27 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 6:47 pm PDT.

How long on average sun shines in September in Snoqualmie?

In Snoqualmie, the average sunshine duration in September is 8.9h.

What is the UV index reading in September in Snoqualmie?

In September, the average daily maximum UV index is 3. A UV Index estimate of 3 to 5 represents a medium hazard to health from unsafe exposure to Sun's UV rays.
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
Snoqualmie, WA

Average temperature in September - Snoqualmie, WA
  • Average high temperature in September: 67.8°F

The warmest month (with the highest average high temperature) is August (74.8°F).
The month with the lowest average high temperature is December (39.7°F).

  • Average low temperature in September: 46°F

The month with the highest average low temperature is August (48.7°F).
The coldest month (with the lowest average low temperature) is December (29.8°F).

Average pressure in September
Snoqualmie, WA

Average pressure in September - Snoqualmie, WA
  • Average pressure in September: 30"Hg

The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is August (29.99"Hg).

Average wind speed in September
Snoqualmie, WA

Average wind speed in September - Snoqualmie, WA
  • Average wind speed in September: 3.5mph

The windiest month (with the highest average wind speed) is January (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.3mph).

Average humidity in September
Snoqualmie, WA

Average humidity in September - Snoqualmie, WA
  • Average humidity in September: 75%

The months with the highest relative humidity are January and February (87%).
The month with the lowest relative humidity is July (71%).

Average rainfall in September
Snoqualmie, WA

Average rainfall in September - Snoqualmie, WA
  • Average rainfall in September: 1.89"

The wettest month (with the highest rainfall) is January (6.1").
The driest months (with the least rainfall) are July and August (0.59").

Average rainfall days in September
Snoqualmie, WA

Average rainfall days in September - Snoqualmie, WA
  • Average rainfall days in September: 12.6 days

The month with the highest number of rainy days is March (20.5 days).
The month with the least rainy days is August (6.4 days).

Average snowfall in September
Snoqualmie, WA

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

The month with the highest snowfall is February (3.94").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Snoqualmie, WA

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

The month with the highest number of snowfall days is February (5.4 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

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

Average daylight in September / Average sunshine in September - Snoqualmie, 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 5min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are January and December (Average sunshine: 3h and 54min).

Average sunshine days in September
Snoqualmie, WA

Average sunshine days in September - Snoqualmie, WA
  • Average sunshine days in September: 16 days

The month with the most sunshine days is August (21.9 days).
The month with the least sunshine days is February (7.8 days).

Average UV index in September
Snoqualmie, WA

Average UV index in September - Snoqualmie, WA
  • Average UV index in September: 3

The month with the highest UV index is July (UV index 5).
The month with the lowest UV index is February (UV index 1).

Average cloud cover in September
Snoqualmie, WA

Average cloud cover in September - Snoqualmie, WA
  • Average cloud cover in September: 39

The months with the most cloud cover are January, February, March and December (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 28).

Average visibility in September
Snoqualmie, WA

Average visibility in September - Snoqualmie, WA
  • Average visibility in September: 5mi

The months with the highest visibility are May, June, July, August, September and October (5mi).
The months with the lowest visibility are January, February, March, April, November and December (4mi).

Snoqualmie, Washington, USA

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