September weather forecast
Clear Lake, WA

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Weather in September

The first month of the autumn, September, is still a comfortable month in Clear Lake, Washington, with temperature in the range of an average low of 47.8°F (8.8°C) and an average high of 64.2°F (17.9°C).

Temperature

September is marked by a subtle drop in average high-temperatures, transitioning from a pleasant 70.7°F (21.5°C) in August to an enjoyable 64.2°F (17.9°C). Clear Lake records an average nighttime low of 47.8°F (8.8°C) in September.

Humidity

In September, the average relative humidity is 79%.

Rainfall

In Clear Lake, Washington, during September, the rain falls for 13.5 days and regularly aggregates up to 2.76" (70mm) of precipitation. In Clear Lake, Washington, during the entire year, the rain falls for 203.2 days and collects up to 49.72" (1263mm) of precipitation.

Snowfall

In Clear Lake, snow does not fall in May through October.

Daylight

In Clear Lake, the average length of the day in September is 12h and 34min.
On the first day of the month, sunrise is at 6:27 am and sunset at 7:49 pm. On the last day of September, in Clear Lake, sunrise is at 7:08 am and sunset at 6:49 pm PDT.

Sunshine

The average sunshine in September in Clear Lake is 8.8h.

UV index

In Clear Lake, the average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the average person.
Note: The average daily UV index of 3 in September transforms into the following instructions:
Make use of precautions - It is urged to ward off sun damage. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
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Frequently asked questions

What are the temperatures in Clear Lake in September?

In Clear Lake, in September, the average high-temperature is 64.2°F (17.9°C), and the average low-temperature is 47.8°F (8.8°C).

What is the average humidity in September in Clear Lake?

In September, the average relative humidity in Clear Lake, Washington, is 79%.

How much does it rain in Clear Lake in September?

In September, in Clear Lake, Washington, the rain falls for 13.5 days. Throughout September, 2.76" (70mm) of precipitation is accumulated.

When it does not snow in Clear Lake?

May through October are months without snowfall in Clear Lake.

What is the average length of the day in September in Clear Lake?

In Clear Lake, the average day length in September is 12h and 34min.

When is the sunrise / sunset in September in Clear Lake?

In September, on the first day of the month, sunrise is at 6:27 am and sunset at 7:49 pm. On the last day of the month, in Clear Lake, Washington, sunrise is at 7:08 am and sunset at 6:49 pm PDT.

How many hours of sunshine does Clear Lake have in September?

In September, the average sunshine duration in Clear Lake is 8.8h.

What is the UV index reading in September in Clear Lake?

In September, the average daily maximum UV index in Clear Lake, Washington, is 3. A UV Index reading of 3 to 5 represents a moderate health threat 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
Clear Lake, WA

Average temperature in September - Clear Lake, WA
  • Average high temperature in September: 64.2°F

The warmest month (with the highest average high temperature) is July (70.9°F).
The month with the lowest average high temperature is December (40.5°F).

  • Average low temperature in September: 47.8°F

The month with the highest average low temperature is August (50.5°F).
The coldest months (with the lowest average low temperature) are February and December (32.5°F).

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Average pressure in September
Clear Lake, WA

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

The month with the highest atmospheric pressure is January (30.09"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).

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Average wind speed in September
Clear Lake, WA

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

The windiest month (with the highest average wind speed) is November (5.7mph).
The calmest month (with the lowest average wind speed) is August (3.3mph).

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Average humidity in September
Clear Lake, WA

Average humidity in September - Clear Lake, WA
  • Average humidity in September: 79%

The months with the highest relative humidity are January, February and March (86%).
The month with the lowest relative humidity is July (75%).

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Average rainfall in September
Clear Lake, WA

Average rainfall in September - Clear Lake, WA
  • Average rainfall in September: 2.76"

The wettest month (with the highest rainfall) is November (7.09").
The driest month (with the least rainfall) is July (0.98").

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Average rainfall days in September
Clear Lake, WA

Average rainfall days in September - Clear Lake, WA
  • Average rainfall days in September: 13.5 days

The month with the highest number of rainy days is March (22.1 days).
The month with the least rainy days is August (9.4 days).

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Average snowfall in September
Clear Lake, WA

Average snowfall in September - Clear Lake, WA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (4.96").
The months with the least snowfall are May, June, July, August, September and October (0").

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Average snowfall days in September
Clear Lake, WA

Average snowfall days in September - Clear Lake, WA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (4.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

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Average daylight in September /
Average sunshine in September
Clear Lake, WA

Average daylight in September / Average sunshine in September - Clear Lake, WA
  • Average daylight in September: 12h and 4min

The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 24min).

  • Average sunshine in September: 8h and 5min

The month with the most sunshine is August (Average sunshine: 10h and 18min).
The month with the least sunshine is December (Average sunshine: 3h and 30min).

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Average sunshine days in September
Clear Lake, WA

Average sunshine days in September - Clear Lake, WA
  • Average sunshine days in September: 14.5 days

The month with the most sunshine days is August (19.2 days).
The month with the least sunshine days is March (7.3 days).

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Average UV index in September
Clear Lake, WA

Average UV index in September - Clear Lake, WA
  • Average UV index in September: 3

The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).

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Average cloud cover in September
Clear Lake, WA

Average cloud cover in September - Clear Lake, WA
  • Average cloud cover in September: 37

The month with the most cloud cover is December (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 28).

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Average visibility in September
Clear Lake, WA

Average visibility in September - Clear Lake, WA
  • Average visibility in September: 5mi

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

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Clear Lake, Washington, USA

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