September weather - Autumn 2024

Weather in September
Frequently asked questions
Average temperature in September
Average pressure in September
Average wind speed in September
Average humidity in September
Average rainfall in September
Average rainfall days in September
Average snowfall in September
Average snowfall days in September
Average daylight in September
Average sunshine in September
Average sunshine days in September
Average UV index in September
Average cloud cover in September
Average visibility in September

Rocks and cliffs around the scenic Spokane Falls in Washington, leading to the vast Spokane River and a view of the high bridge out front

Weather in September

As September steps in, Spokane transitions from scorching summer towards the bountiful harvest season. With a significant drop to an average of 72.9°F (22.7°C), the temperature cools down, hinting at summer's end. Rainfall slightly ascends once again to 0.63" (16mm), marking the start of autumn's transient tears. Whispers of change ripple across the winds as their speed flutters uncertainly. Corners of Spokane begin to glow with autumnal hues, embracing the lowered pace of daylight hours.

Temperature

The onset of September introduces a moderate change in Spokane's weather, with average high-temperatures falling from August's moderately hot 83.7°F (28.7°C) to a pleasant 72.9°F (22.7°C). September nights in Spokane report a substantial dip from daytime highs to an average of 50.7°F (10.4°C).

Humidity

The average relative humidity in September is 48%.

Rainfall

In Spokane, Washington, in September, it is raining for 7.5 days, with typically 0.63" (16mm) of accumulated precipitation. In Spokane, during the entire year, the rain falls for 127.8 days and collects up to 16.93" (430mm) of precipitation.

Snowfall

January through May, September through December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.47" (12mm) of snow. Throughout the year, there are 62.3 snowfall days, and 37.83" (961mm) of snow is accumulated.

Daylight

The average length of the day in September in Spokane, Washington, is 12h and 33min.
On the first day of the month, sunrise is at 6:09 am and sunset at 7:29 pm. On the last day of September, in Spokane, Washington, sunrise is at 6:48 am and sunset at 6:30 pm PDT.

Sunshine

The average sunshine in September is 10.2h.

UV index

In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the ordinary person.
Note: The maximum daily UV index of 4 during September translates into the following directions:
Take precautions - Protection against sun damage is advised. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Bear in mind! The Sun's UV radiation can nearly double in intensity due to the reflective quality of snow.

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Frequently asked questions

What is the temperature in September in Spokane?

The high-temperature during September is 72.9°F (22.7°C) and the low-temperature is 50.7°F (10.4°C). In July, the average heat index (a.k.a. 'apparent temperature', 'feels like'), which calculates the temperature value influenced by the moisture in the air, is evaluated at 82.4°F (28°C).

What is the average humidity in September in Spokane?

In Spokane, the average relative humidity in September is 48%.

How many days does it rain in September in Spokane?

In September, in Spokane, Washington, the rain falls for 7.5 days. Throughout September, 0.63" (16mm) of precipitation is accumulated.

When does it start to snow in Spokane?

September is the first month it typically snows in Spokane. Throughout September, in the average 0.2 snowfall days, it receives 0.47" (12mm) of snow.

How many hours of daylight does Spokane have in September?

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

When is the sunrise / sunset in September in Spokane?

On the first day of September in Spokane, sunrise is at 6:09 am and sunset at 7:29 pm. On the last day of the month, sunrise is at 6:48 am and sunset at 6:30 pm PDT.

How long on average sun shines in September in Spokane?

The average sunshine duration in September is 10.2h.

What is the UV index intensity in September in Spokane?

In Spokane, Washington, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health risk from unprotected exposure to UV radiation.

Today

Tomorrow

Long-term

Year J F M A M J J A September O N D

Aug

September

Oct

Average high temperature

83.7°F 28.7°C

72.9°F 22.7°C

55.9°F 13.3°C

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

6.3mph 10.1km/h

6.2mph 10km/h

6.7mph 10.8km/h

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

Average daylight

Average sunshine

Average sunshine days

22.3

20.3

16.6

Average UV index

Average cloud cover

Average visibility

Average temperature in September
Spokane, WA

Average high temperature in September: 72.9°F

The warmest months (with the highest average high temperature) are July and August (83.7°F).
The month with the lowest average high temperature is December (32.2°F).

Average low temperature in September: 50.7°F

The month with the highest average low temperature is August (59°F).
The coldest month (with the lowest average low temperature) is December (22.1°F).

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Average pressure in September
Spokane, 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 (29.9"Hg).

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Average wind speed in September
Spokane, WA

Average wind speed in September: 5.9mph

The windiest month (with the highest average wind speed) is April (7.3mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).

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Average humidity in September
Spokane, WA

Average humidity in September: 48%

The month with the highest relative humidity is January (89%).
The month with the lowest relative humidity is August (38%).

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Average rainfall in September
Spokane, WA

Average rainfall in September: 0.63"

The wettest month (with the highest rainfall) is March (2.13").
The driest month (with the least rainfall) is August (0.35").

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Average rainfall days in September
Spokane, WA

Average rainfall days in September: 7.5 days

The month with the highest number of rainy days is April (16.3 days).
The month with the least rainy days is July (4.9 days).

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Average snowfall in September
Spokane, WA

Average snowfall in September: 0.47"

The month with the highest snowfall is January (10.39").
The months with the least snowfall are June, July and August (0").

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Average snowfall days in September
Spokane, WA

Average snowfall days in September: 0.2 days

The month with the highest number of snowfall days is December (15.6 days).
The months with the least snowfall days are June, July and August (0 days).

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Average daylight in September /
Average sunshine in September
Spokane, 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 month with the least sunshine is December (Average sunshine: 3h and 54min).

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Average sunshine days in September
Spokane, WA

Average sunshine days in September: 20.3 days

The month with the most sunshine days is July (24.1 days).
The month with the least sunshine days is March (9.8 days).

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Average UV index in September
Spokane, WA

Average UV index in September: 4

The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are February and December (UV index 1).

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Average cloud cover in September
Spokane, WA

Average cloud cover in September: 20

The months with the most cloud cover are January and December (Cloud cover 59).
The months with the least cloud cover are July and August (Cloud cover 13).

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Average visibility in September
Spokane, 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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September weather forecast
Spokane, WA

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