September weather forecast
Coulee City, WA

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Weather in September

September, the first month of the autumn in Coulee City, is also an agreeable month, with an average temperature fluctuating between 53.2°F (11.8°C) and 72.7°F (22.6°C).

Temperature

The onset of September results in a decrease in the average high-temperature, receding from a warm 84.2°F (29°C) in August to an agreeable 72.7°F (22.6°C). In September, the temperature drops to an average of 53.2°F (11.8°C) at night.

Humidity

The average relative humidity in September is 45%.

Rainfall

In Coulee City, during September, the rain falls for 5.5 days and regularly aggregates up to 0.43" (11mm) of precipitation. Throughout the year, in Coulee City, there are 102.1 rainfall days, and 9.65" (245mm) of precipitation is accumulated.

Snowfall

January through April, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.08" (2mm) of snow. Throughout the year, there are 33.4 snowfall days, and 14.65" (372mm) of snow is accumulated.

Daylight

The average length of the day in September in Coulee City is 12h and 33min.
On the first day of September, sunrise is at 6:16 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 6:56 am and sunset at 6:37 pm PDT.

Sunshine

The average sunshine in September is 10.7h.

UV index

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for average individuals.
Note: In September, a daily UV index of 4 turns into the following recommendations:
Be vigilant - Suggestions to stave off sun damage are provided. It's recommended to limit sun exposure when its radiation is at its peak during midday. Enhance your sun protection with tightly woven, yet airy clothing. Be attentive! The reflective property of snow can nearly double the Sun's UV radiation.
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Frequently asked questions

What is the temperature in September in Coulee City?

Coulee City in September has an average high-temperature of 72.7°F (22.6°C) and an average low-temperature of 53.2°F (11.8°C).

What is the average humidity in September in Coulee City?

In September, the average relative humidity is 45%.

How many days does it rain in September in Coulee City?

In Coulee City, in September, during 5.5 rainfall days, 0.43" (11mm) of precipitation is typically accumulated.

When does it start to snow in Coulee City?

September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.08" (2mm) of snow.

How many hours of daylight does Coulee City have in September?

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

When is the sunrise / sunset in September in Coulee City?

On the first day of September, sunrise is at 6:16 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 6:56 am and sunset at 6:37 pm PDT.

How long on average sun shines in September in Coulee City?

In Coulee City, Washington, the average sunshine duration in September is 10.7h.

How high is the UV index in September in Coulee City?

In Coulee City, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health risk 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
Coulee City, WA

Average temperature in September - Coulee City, WA
  • Average high temperature in September: 72.7°F

The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is December (31.6°F).

  • Average low temperature in September: 53.2°F

The month with the highest average low temperature is August (61.3°F).
The coldest month (with the lowest average low temperature) is December (21.4°F).

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Average pressure in September
Coulee City, WA

Average pressure in September - Coulee City, WA
  • Average pressure in September: 29.96"Hg

The month with the highest atmospheric pressure is January (30.18"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).

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Average wind speed in September
Coulee City, WA

Average wind speed in September - Coulee City, WA
  • Average wind speed in September: 5.8mph

The windiest month (with the highest average wind speed) is April (7mph).
The calmest month (with the lowest average wind speed) is January (4.9mph).

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Average humidity in September
Coulee City, WA

Average humidity in September - Coulee City, WA
  • Average humidity in September: 45%

The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (36%).

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Average rainfall in September
Coulee City, WA

Average rainfall in September - Coulee City, WA
  • Average rainfall in September: 0.43"

The wettest months (with the highest rainfall) are May and December (1.18").
The driest months (with the least rainfall) are July and August (0.2").

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Average rainfall days in September
Coulee City, WA

Average rainfall days in September - Coulee City, WA
  • Average rainfall days in September: 5.5 days

The month with the highest number of rainy days is March (12.1 days).
The month with the least rainy days is August (3.2 days).

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Average snowfall in September
Coulee City, WA

Average snowfall in September - Coulee City, WA
  • Average snowfall in September: 0.08"

The month with the highest snowfall is January (4.41").
The months with the least snowfall are May, June, July and August (0").

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Average snowfall days in September
Coulee City, WA

Average snowfall days in September - Coulee City, WA
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is December (10.5 days).
The months with the least snowfall days are May, June, July and August (0 days).

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Average daylight in September /
Average sunshine in September
Coulee City, WA

Average daylight in September / Average sunshine in September - Coulee City, 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 month with the most sunshine is August (Average sunshine: 12h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).

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Average sunshine days in September
Coulee City, WA

Average sunshine days in September - Coulee City, WA
  • Average sunshine days in September: 23.3 days

The month with the most sunshine days is August (25.8 days).
The month with the least sunshine days is March (14.7 days).

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Average UV index in September
Coulee City, WA

Average UV index in September - Coulee City, WA
  • Average UV index in September: 4

The month with the highest UV index is July (UV index 7).
The month with the lowest UV index is November (UV index 1).

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Average cloud cover in September
Coulee City, WA

Average cloud cover in September - Coulee City, WA
  • Average cloud cover in September: 18

The month with the most cloud cover is January (Cloud cover 55).
The months with the least cloud cover are July and August (Cloud cover 12).

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Average visibility in September
Coulee City, WA

Average visibility in September - Coulee City, WA
  • Average visibility in September: 6mi

The months with the highest visibility are March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (4mi).

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Coulee City, Washington, USA

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