September weather forecast
Bonney Lake, WA

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Weather in September

The first month of the autumn, September, is still a pleasant month in Bonney Lake, Washington, with an average temperature fluctuating between 68.9°F (20.5°C) and 47.7°F (8.7°C).

Temperature

A modest decline in the average high-temperature is seen during September, decreasing from a warm 75.7°F (24.3°C) in August to a pleasant 68.9°F (20.5°C). Bonney Lake in September experiences a low-temperature average of 47.7°F (8.7°C).

Humidity

The average relative humidity in September is 75%.

Rainfall

In Bonney Lake, during September, the rain falls for 12.2 days and regularly aggregates up to 1.61" (41mm) of precipitation. In Bonney Lake, during the entire year, the rain falls for 185 days and collects up to 35.71" (907mm) of precipitation.

Snowfall

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

Daylight

In Bonney Lake, the average length of the day in September is 12h and 32min.
On the first day of the month, sunrise is at 6:29 am and sunset at 7:47 pm. On the last day of September, sunrise is at 7:07 am and sunset at 6:49 pm PDT.

Sunshine

The average sunshine in September is 9.3h.

UV index

The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.
Note: The maximum daily UV index of 4 in September converts into the following recommendations:
Make use of precautions - Shielding skin and eyes from injury is a requirement. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Stay sun-safe with clothing that is both closely woven and worn loosely.
Updated: Jun 10, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Bonney Lake in September?

An average high-temperature, in September, in Bonney Lake, is 68.9°F (20.5°C) and the average low-temperature is 47.7°F (8.7°C).

What is the average humidity in September?

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

How many days does it rain in September?

In Bonney Lake, in September, during 12.2 rainfall days, 1.61" (41mm) of precipitation is typically accumulated.

When it does not snow?

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

How many hours of daylight does Bonney Lake have in September?

The average day length in September is 12h and 32min.

When are sunrise and sunset in September in Bonney Lake?

On the first day of September in Bonney Lake, sunrise is at 6:29 am and sunset at 7:47 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 Bonney Lake have in September?

In Bonney Lake, Washington, the average sunshine duration in September is 9.3h.

What is the UV index intensity in September?

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

Average temperature in September - Bonney Lake, WA
  • Average high temperature in September: 68.9°F

The warmest month (with the highest average high temperature) is August (75.7°F).
The month with the lowest average high temperature is December (41.4°F).

  • Average low temperature in September: 47.7°F

The month with the highest average low temperature is August (50.9°F).
The coldest month (with the lowest average low temperature) is December (32°F).

Average pressure in September
Bonney Lake, WA

Average pressure in September - Bonney Lake, 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
Bonney Lake, WA

Average wind speed in September - Bonney Lake, WA
  • Average wind speed in September: 3.7mph

The windiest month (with the highest average wind speed) is January (4.9mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).

Average humidity in September
Bonney Lake, WA

Average humidity in September - Bonney Lake, WA
  • Average humidity in September: 75%

The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are July and August (70%).

Average rainfall in September
Bonney Lake, WA

Average rainfall in September - Bonney Lake, WA
  • Average rainfall in September: 1.61"

The wettest month (with the highest rainfall) is December (5.35").
The driest month (with the least rainfall) is July (0.51").

Average rainfall days in September
Bonney Lake, WA

Average rainfall days in September - Bonney Lake, WA
  • Average rainfall days in September: 12.2 days

The month with the highest number of rainy days is March (20.7 days).
The month with the least rainy days is August (6.8 days).

Average snowfall in September
Bonney Lake, WA

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

The month with the highest snowfall is February (3.31").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Bonney Lake, WA

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

The month with the highest number of snowfall days is February (5.3 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
Bonney Lake, WA

Average daylight in September / Average sunshine in September - Bonney Lake, 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 36min).

  • Average sunshine in September: 9h and 2min

The month with the most sunshine is August (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 4h and 12min).

Average sunshine days in September
Bonney Lake, WA

Average sunshine days in September - Bonney Lake, WA
  • Average sunshine days in September: 16.9 days

The month with the most sunshine days is August (22 days).
The month with the least sunshine days is February (8.2 days).

Average UV index in September
Bonney Lake, WA

Average UV index in September - Bonney Lake, 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, October, November and December (UV index 2).

Average cloud cover in September
Bonney Lake, WA

Average cloud cover in September - Bonney Lake, WA
  • Average cloud cover in September: 35

The months with the most cloud cover are January and December (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 25).

Average visibility in September
Bonney Lake, WA

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

The months with the highest visibility are July and August (6mi).
The months with the lowest visibility are January, February and December (4mi).

Bonney Lake, Washington, USA

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