September weather forecast
Liberty Lake, WA

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Weather in September

The first month of the autumn, September, is still a pleasant month in Liberty Lake, Washington, with temperature in the range of an average high of 72.5°F (22.5°C) and an average low of 48.2°F (9°C).

Temperature

September ushers in a slight temperature change, with average high-temperatures reducing from August's warm 83.3°F (28.5°C) to an agreeable 72.5°F (22.5°C). Despite the stark contrast with daytime temperatures, Liberty Lake's September nights average at a frosty 48.2°F (9°C).

Humidity

The average relative humidity in September is 52%.

Rainfall

In Liberty Lake, during September, the rain falls for 7.9 days and regularly aggregates up to 0.63" (16mm) of precipitation. Throughout the year, in Liberty Lake, there are 125.4 rainfall days, and 17.28" (439mm) of precipitation is accumulated.

Snowfall

Months with snowfall are January through May, September through December. September is the first month it typically snows in Liberty Lake, Washington. Throughout September, in the average 0.2 snowfall days, it receives 0.35" (9mm) of snow. In Liberty Lake, during the entire year, snow falls for 56.4 days and aggregates up to 37.4" (950mm) of snow.

Daylight

In Liberty Lake, Washington, the average length of the day in September is 12h and 33min.
On the first day of September in Liberty Lake, sunrise is at 6:08 am and sunset at 7:28 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:29 pm PDT.

Sunshine

In September, the average sunshine in Liberty Lake is 10.1h.

UV index

The average daily maximum UV index in September in Liberty Lake, Washington, is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.
Note: During September, 4 as the daily maximum UV index converts into the following advice:
Be vigilant - Preventing sunburn is recommended. UV radiation is strongest from the Sun during midday; protect yourself by staying in shaded areas. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Updated: Feb 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature in Liberty Lake?

In September, in Liberty Lake, the average high-temperature is 72.5°F (22.5°C), and the average low-temperature is 48.2°F (9°C). The average heat index (a.k.a. 'real feel', 'apparent temperature'), which combines relative humidity and air temperature, in August is calculated to be 82.4°F (28°C).

What is the average humidity in September in Liberty Lake?

The average relative humidity in September in Liberty Lake is 52%.

How many days does it rain in September in Liberty Lake?

In Liberty Lake, in September, during 7.9 rainfall days, 0.63" (16mm) of precipitation is typically accumulated.

When does it start to snow in Liberty Lake?

September is the first month it typically snows in Liberty Lake, Washington. Throughout September, in the average 0.2 snowfall days, it receives 0.35" (9mm) of snow.

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

In Liberty Lake, Washington, the average day length in September is 12h and 33min.

What time are sunrise and sunset in September in Liberty Lake?

On the first day of September, sunrise is at 6:08 am and sunset at 7:28 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:29 pm PDT.

How long on average sun shines in September in Liberty Lake?

The average sunshine duration in September in Liberty Lake, Washington, is 10.1h.

What is the UV index intensity in September in Liberty Lake?

The average daily maximum UV index in September in Liberty Lake is 4. A UV Index of 3 to 5 symbolizes a medium health risk from unprotected exposure to 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
Liberty Lake, WA

Average temperature in September - Liberty Lake, WA
  • Average high temperature in September: 72.5°F

The warmest month (with the highest average high temperature) is August (83.3°F).
The month with the lowest average high temperature is December (32°F).

  • Average low temperature in September: 48.2°F

The month with the highest average low temperature is August (55.9°F).
The coldest month (with the lowest average low temperature) is December (21.9°F).

Average pressure in September
Liberty Lake, WA

Average pressure in September - Liberty Lake, WA
  • Average pressure in September: 29.96"Hg

The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).

Average wind speed in September
Liberty Lake, WA

Average wind speed in September - Liberty Lake, WA
  • Average wind speed in September: 4.9mph

The windiest month (with the highest average wind speed) is April (6.1mph).
The calmest month (with the lowest average wind speed) is December (4.7mph).

Average humidity in September
Liberty Lake, WA

Average humidity in September - Liberty Lake, WA
  • Average humidity in September: 52%

The month with the highest relative humidity is January (91%).
The month with the lowest relative humidity is August (43%).

Average rainfall in September
Liberty Lake, WA

Average rainfall in September - Liberty Lake, WA
  • Average rainfall in September: 0.63"

The wettest month (with the highest rainfall) is January (2.28").
The driest months (with the least rainfall) are July and August (0.35").

Average rainfall days in September
Liberty Lake, WA

Average rainfall days in September - Liberty Lake, WA
  • Average rainfall days in September: 7.9 days

The month with the highest number of rainy days is March (16 days).
The month with the least rainy days is July (5.1 days).

Average snowfall in September
Liberty Lake, WA

Average snowfall in September - Liberty Lake, WA
  • Average snowfall in September: 0.35"

The month with the highest snowfall is January (10.51").
The months with the least snowfall are June, July and August (0").

Average snowfall days in September
Liberty Lake, WA

Average snowfall days in September - Liberty Lake, WA
  • Average snowfall days in September: 0.2 days

The month with the highest number of snowfall days is December (13.9 days).
The months with the least snowfall days are June, July and August (0 days).

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

Average daylight in September / Average sunshine in September - Liberty 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 30min).

  • Average sunshine in September: 10h and 1min

The month with the most sunshine is August (Average sunshine: 12h and 0min).
The months with the least sunshine are January and December (Average sunshine: 3h and 48min).

Average sunshine days in September
Liberty Lake, WA

Average sunshine days in September - Liberty Lake, WA
  • Average sunshine days in September: 20.8 days

The month with the most sunshine days is July (24.3 days).
The month with the least sunshine days is March (10.3 days).

Average UV index in September
Liberty Lake, WA

Average UV index in September - Liberty Lake, WA
  • Average UV index in September: 4

The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in September
Liberty Lake, WA

Average cloud cover in September - Liberty Lake, WA
  • Average cloud cover in September: 21

The month with the most cloud cover is January (Cloud cover 62).
The months with the least cloud cover are July and August (Cloud cover 13).

Average visibility in September
Liberty Lake, WA

Average visibility in September - Liberty Lake, 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 and December (4mi).

Liberty Lake, Washington, USA

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