September weather forecast
Cascadia, OR

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Weather in September

The first month of the autumn, September, is also an agreeable month in Cascadia, Oregon, with an average temperature varying between 72.3°F (22.4°C) and 47.3°F (8.5°C).

Temperature

As August transitions into September, Cascadia sees a gentle drop in the average high-temperature, transitioning from a warm 79.5°F (26.4°C) to an agreeable 72.3°F (22.4°C). Cascadia registers a pronounced decline from daytime peak temperatures, averaging a frosty 47.3°F (8.5°C) lows in September.

Humidity

In Cascadia, the average relative humidity in September is 71%.

Rainfall

In September, in Cascadia, the rain falls for 9 days. Throughout September, 1.61" (41mm) of precipitation is accumulated. Throughout the year, in Cascadia, there are 167.6 rainfall days, and 36.54" (928mm) of precipitation is accumulated.

Snowfall

In Cascadia, snow does not fall in May through October.

Daylight

In Cascadia, the average length of the day in September is 12h and 30min.
On the first day of September, sunrise is at 6:33 am and sunset at 7:45 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:51 pm PDT.

Sunshine

In Cascadia, the average sunshine in September is 9.5h.

UV index

In September, the average daily maximum UV index in Cascadia, Oregon, is 3. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for average individuals.
Note: In September, the maximum UV index of 3 suggests this advice:
Exercise care. People with light skin might get burns in fewer than 30 minutes. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
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Frequently asked questions

What is the usual temperature for Cascadia in September?

In Cascadia, 72.3°F (22.4°C) is the average high-temperature and 47.3°F (8.5°C) is the average low-temperature during September.

What is the average humidity in September in Cascadia?

In Cascadia, the average relative humidity in September is 71%.

How much does it rain in Cascadia in September?

In Cascadia, in September, it is raining for 9 days, with typically 1.61" (41mm) of accumulated precipitation.

When it does not snow in Cascadia?

In Cascadia, snow does not fall in May through October.

What is the average length of the day in September in Cascadia?

In September, the average day length in Cascadia, Oregon, is 12h and 30min.

When are sunrise and sunset in September in Cascadia?

In September, on the first day of the month, sunrise is at 6:33 am and sunset at 7:45 pm. On the last day of the month, in Cascadia, sunrise is at 7:07 am and sunset at 6:51 pm PDT.

How long on average sun shines in September in Cascadia?

In Cascadia, the average sunshine duration in September is 9.5h.

What is the UV index reading in September in Cascadia?

The average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a medium health risk 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
Cascadia, OR

Average temperature in September - Cascadia, OR
  • Average high temperature in September: 72.3°F

The warmest month (with the highest average high temperature) is August (79.5°F).
The month with the lowest average high temperature is December (44.4°F).

  • Average low temperature in September: 47.3°F

The month with the highest average low temperature is August (49.8°F).
The coldest month (with the lowest average low temperature) is December (32.9°F).

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Average pressure in September
Cascadia, OR

Average pressure in September - Cascadia, OR
  • Average pressure in September: 30.01"Hg

The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).

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Average wind speed in September
Cascadia, OR

Average wind speed in September - Cascadia, OR
  • Average wind speed in September: 3.9mph

The windiest month (with the highest average wind speed) is January (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.7mph).

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Average humidity in September
Cascadia, OR

Average humidity in September - Cascadia, OR
  • Average humidity in September: 71%

The months with the highest relative humidity are February, March and December (86%).
The month with the lowest relative humidity is August (66%).

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Average rainfall in September
Cascadia, OR

Average rainfall in September - Cascadia, OR
  • Average rainfall in September: 1.61"

The wettest month (with the highest rainfall) is December (5.47").
The driest month (with the least rainfall) is July (0.24").

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Average rainfall days in September
Cascadia, OR

Average rainfall days in September - Cascadia, OR
  • Average rainfall days in September: 9 days

The month with the highest number of rainy days is March (21.1 days).
The month with the least rainy days is July (4.1 days).

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Average snowfall in September
Cascadia, OR

Average snowfall in September - Cascadia, OR
  • Average snowfall in September: 0"

The month with the highest snowfall is February (3.7").
The months with the least snowfall are May, June, July, August, September and October (0").

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Average snowfall days in September
Cascadia, OR

Average snowfall days in September - Cascadia, OR
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (3.4 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

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Average daylight in September /
Average sunshine in September
Cascadia, OR

Average daylight in September / Average sunshine in September - Cascadia, OR
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).

  • Average sunshine in September: 9h and 3min

The month with the most sunshine is August (Average sunshine: 11h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 6min).

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Average sunshine days in September
Cascadia, OR

Average sunshine days in September - Cascadia, OR
  • Average sunshine days in September: 19.3 days

The month with the most sunshine days is July (25.7 days).
The month with the least sunshine days is February (8.4 days).

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Average UV index in September
Cascadia, OR

Average UV index in September - Cascadia, OR
  • Average UV index in September: 3

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

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Average cloud cover in September
Cascadia, OR

Average cloud cover in September - Cascadia, OR
  • Average cloud cover in September: 30

The months with the most cloud cover are February and March (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 19).

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Average visibility in September
Cascadia, OR

Average visibility in September - Cascadia, OR
  • Average visibility in September: 5mi

The month with the highest visibility is August (6mi).
The months with the lowest visibility are February and April (4mi).

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Cascadia, Oregon, USA

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