September weather forecast
Kirkland, WA

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Weather in September

September marks an emphatic shift towards autumn with a notable dip in temperature from the summer livelihood. Specific climatic patterns mimic August, with a steady decline in warmth observed as the month progresses. Although summer relinquishes its hold, September continues to benefit from long hours of daylight and warm weather. Despite the minor decrease in temperature, the handsome blend of summer and autumn sets a captivating tone throughout the city.

Temperature

The arrival of September suggests a slight decrease in the average high-temperature, moving from a moderately hot 75.9°F (24.4°C) in August to a pleasant 69.3°F (20.7°C). Throughout the month of September, Kirkland witnesses an average temperature of 50.2°F (10.1°C).

Humidity

The average relative humidity in September is 75%.

Rainfall

In September, in Kirkland, the rain falls for 10.9 days. Throughout September, 1.3" (33mm) of precipitation is accumulated. Throughout the year, in Kirkland, there are 175.1 rainfall days, and 28.58" (726mm) of precipitation is accumulated.

Snowfall

In Kirkland, snow does not fall in May through October.

Daylight

In September, the average length of the day is 12h and 33min.
On the first day of the month, sunrise is at 6:28 am and sunset at 7:48 pm. On the last day of September, sunrise is at 7:07 am and sunset at 6:49 pm PDT.

Sunshine

In September, the average sunshine is 9.4h.

UV index

The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.
Note: The maximum daily UV index of 4 in September converts into the following recommendations:
Prioritize safety - The need to safeguard skin and eyes from harm is emphasized. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. A wide-brimmed hat is a staple for defending the face, eyes, ears, and neck from the Sun.

Frequently asked questions

What is the usual temperature for Kirkland in September?

In September, in Kirkland, the average high-temperature is 69.3°F (20.7°C), and the average low-temperature is 50.2°F (10.1°C).

What is the average humidity in September?

In September, the average relative humidity is 75%.

How many days does it rain in September?

In Kirkland, during September, the rain falls for 10.9 days and regularly aggregates up to 1.3" (33mm) of precipitation.

When it does not snow?

In Kirkland, snow does not fall in May through October.

What is the average length of the day in September?

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

When is the sunrise / sunset in September?

On the first day of September, sunrise is at 6:28 am and sunset at 7:48 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:49 pm PDT.

How many hours of sunshine does Kirkland have in September?

In Kirkland, the average sunshine duration in September is 9.4h.

How high is the UV index in September?

In Kirkland, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate vulnerability from 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
Kirkland, WA

Average temperature in September - Kirkland, WA
  • Average high temperature in September: 69.3°F

The warmest month (with the highest average high temperature) is August (75.9°F).
The month with the lowest average high temperature is December (42.8°F).

  • Average low temperature in September: 50.2°F

The month with the highest average low temperature is August (53.2°F).
The coldest month (with the lowest average low temperature) is December (34.7°F).

Average pressure in September
Kirkland, WA

Average pressure in September - Kirkland, WA
  • Average pressure in September: 30.01"Hg

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).

Average wind speed in September
Kirkland, WA

Average wind speed in September - Kirkland, WA
  • Average wind speed in September: 3.8mph

The windiest months (with the highest average wind speed) are January and March (5.2mph).
The calmest month (with the lowest average wind speed) is August (3.4mph).

Average humidity in September
Kirkland, WA

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

The month with the highest relative humidity is January (85%).
The month with the lowest relative humidity is July (70%).

Average rainfall in September
Kirkland, WA

Average rainfall in September - Kirkland, WA
  • Average rainfall in September: 1.3"

The wettest month (with the highest rainfall) is December (4.21").
The driest month (with the least rainfall) is July (0.43").

Average rainfall days in September
Kirkland, WA

Average rainfall days in September - Kirkland, WA
  • Average rainfall days in September: 10.9 days

The month with the highest number of rainy days is March (19.9 days).
The month with the least rainy days is August (6.1 days).

Average snowfall in September
Kirkland, WA

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

The month with the highest snowfall is February (2.95").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Kirkland, WA

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

The month with the highest number of snowfall days is February (3.9 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
Kirkland, WA

Average daylight in September / Average sunshine in September - Kirkland, 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: 9h and 2min

The month with the most sunshine is August (Average sunshine: 10h and 42min).
The months with the least sunshine are January and December (Average sunshine: 4h and 24min).

Average sunshine days in September
Kirkland, WA

Average sunshine days in September - Kirkland, WA
  • Average sunshine days in September: 16.5 days

The month with the most sunshine days is August (22.8 days).
The month with the least sunshine days is March (8.9 days).

Average UV index in September
Kirkland, WA

Average UV index in September - Kirkland, 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
Kirkland, WA

Average cloud cover in September - Kirkland, WA
  • Average cloud cover in September: 33

The months with the most cloud cover are January and December (Cloud cover 55).
The month with the least cloud cover is August (Cloud cover 25).

Average visibility in September
Kirkland, WA

Average visibility in September - Kirkland, WA
  • Average visibility in September: 6mi

The months with the highest visibility are April, May, June, July, August, September and October (6mi).
The months with the lowest visibility are January, February, March, November and December (5mi).

Kirkland, Washington, USA

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