September weather forecast
Chelan Falls, WA

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Weather in September

September, the first month of the autumn in Chelan Falls, is also an agreeable month, with an average temperature ranging between min 49.1°F (9.5°C) and max 70.5°F (21.4°C).

Temperature

Arrival of September comes with a reduction in the average high-temperature, falling from a moderately hot 81.9°F (27.7°C) in August to a pleasant 70.5°F (21.4°C). The average low-temperature of 49.1°F (9.5°C) is witnessed in Chelan Falls during September.

Humidity

The average relative humidity in September is 52%.

Rainfall

In September, the rain falls for 6.7 days. Throughout September, 0.55" (14mm) of precipitation is accumulated. In Chelan Falls, during the entire year, the rain falls for 99.9 days and collects up to 10.47" (266mm) of precipitation.

Snowfall

January through April, September through December are months with snowfall. September is the first month it typically snows in Chelan Falls, Washington. Throughout September, in the average 0.3 snowfall days, it receives 0.71" (18mm) of snow. In Chelan Falls, during the entire year, snow falls for 48.7 days and aggregates up to 28.62" (727mm) of snow.

Daylight

The average length of the day in September is 12h and 33min.
On the first day of September, sunrise is at 6:19 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:40 pm PDT.

Sunshine

In Chelan Falls, the average sunshine in September is 10.7h.

UV index

In Chelan Falls, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the average person.
Note: The daily high UV index of 4 in September translates into this advice:
Make use of precautions - Shielding skin and eyes from injury is a requirement. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Enhance your sun protection with tightly woven, yet airy clothing. Notice! The UV radiation of the Sun can be intensified nearly twofold due to the reflective quality of snow.
Updated: Jul 16, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

An average high-temperature, in September, in Chelan Falls, is 70.5°F (21.4°C) and the average low-temperature is 49.1°F (9.5°C). The average heat index (a.k.a. 'real feel', 'feels like'), which factors the actual air temperature with the relative humidity, in August is estimated at 82.4°F (28°C).

What is the average humidity in September?

In Chelan Falls, the average relative humidity in September is 52%.

How many days does it rain in September?

In Chelan Falls, in September, it is raining for 6.7 days, with typically 0.55" (14mm) of accumulated precipitation.

When does it start to snow?

September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 0.71" (18mm) of snow.

How many hours of daylight does Chelan Falls have in September?

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

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:19 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:40 pm PDT.

How many hours of sunshine does Chelan Falls have in September?

In Chelan Falls, the average sunshine duration in September is 10.7h.

What is the UV index reading in September?

In Chelan Falls, the average daily maximum UV index in September is 4. A UV Index estimate 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
Chelan Falls, WA

Average temperature in September - Chelan Falls, WA
  • Average high temperature in September: 70.5°F

The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is December (30.2°F).

  • Average low temperature in September: 49.1°F

The month with the highest average low temperature is August (55.8°F).
The coldest months (with the lowest average low temperature) are January and December (19°F).

Average pressure in September
Chelan Falls, WA

Average pressure in September - Chelan Falls, WA
  • Average pressure in September: 29.97"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is August (29.93"Hg).

Average wind speed in September
Chelan Falls, WA

Average wind speed in September - Chelan Falls, WA
  • Average wind speed in September: 5.3mph

The windiest month (with the highest average wind speed) is June (6.1mph).
The calmest months (with the lowest average wind speed) are January and December (3.5mph).

Average humidity in September
Chelan Falls, WA

Average humidity in September - Chelan Falls, WA
  • Average humidity in September: 52%

The month with the highest relative humidity is January (90%).
The months with the lowest relative humidity are July and August (43%).

Average rainfall in September
Chelan Falls, WA

Average rainfall in September - Chelan Falls, WA
  • Average rainfall in September: 0.55"

The wettest month (with the highest rainfall) is December (1.65").
The driest month (with the least rainfall) is July (0.16").

Average rainfall days in September
Chelan Falls, WA

Average rainfall days in September - Chelan Falls, WA
  • Average rainfall days in September: 6.7 days

The month with the highest number of rainy days is March (12.8 days).
The month with the least rainy days is August (3.8 days).

Average snowfall in September
Chelan Falls, WA

Average snowfall in September - Chelan Falls, WA
  • Average snowfall in September: 0.71"

The month with the highest snowfall is December (9.06").
The months with the least snowfall are May, June, July and August (0").

Average snowfall days in September
Chelan Falls, WA

Average snowfall days in September - Chelan Falls, WA
  • Average snowfall days in September: 0.3 days

The month with the highest number of snowfall days is January (12 days).
The months with the least snowfall days are May, June, July and August (0 days).

Average daylight in September /
Average sunshine in September
Chelan Falls, WA

Average daylight in September / Average sunshine in September - Chelan Falls, 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 4min

The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

Average sunshine days in September
Chelan Falls, WA

Average sunshine days in September - Chelan Falls, WA
  • Average sunshine days in September: 21.7 days

The month with the most sunshine days is July (25.7 days).
The month with the least sunshine days is March (13.2 days).

Average UV index in September
Chelan Falls, WA

Average UV index in September - Chelan Falls, WA
  • Average UV index in September: 4

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).

Average cloud cover in September
Chelan Falls, WA

Average cloud cover in September - Chelan Falls, WA
  • Average cloud cover in September: 19

The month with the most cloud cover is January (Cloud cover 54).
The months with the least cloud cover are July and August (Cloud cover 12).

Average visibility in September
Chelan Falls, WA

Average visibility in September - Chelan Falls, 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).

Chelan Falls, Washington, USA

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