September weather forecast
Pendleton, OR

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These large silos and creatively shaped red barns stand in the middle of a vast field of harvested wheat, in Pendleton, Oregon
These large silos and creatively shaped red barns stand in the middle of a vast field of harvested wheat, in Pendleton, Oregon

Weather in September

September's weather showcases cooling temperatures as Pendleton transitions slowly towards autumn. With a noticeable reduction in daylight and similar decrease in sunshine hours compared to August, September marks the soft closure of the summer season. Despite this, the pleasant weather offers an ideal opportunity for enjoying outdoor pursuits before winter sets in. Do remember, though, that while the conditions are generally soothing, there's a possible increase in wind speeds to deal with.

Temperature

The arrival of September corresponds with a shift in temperature, down from a warm 84°F (28.9°C) in August to a still moderately hot 74.1°F (23.4°C). Throughout September, Pendleton records an average temperature of 54.7°F (12.6°C) at night.

Humidity

In September, the average relative humidity is 46%.

Rainfall

In Pendleton, in September, during 7 rainfall days, 0.51" (13mm) of precipitation is typically accumulated. In Pendleton, during the entire year, the rain falls for 132.7 days and collects up to 12.91" (328mm) of precipitation.

Snowfall

Months with snowfall are January through April, September, November and December. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.08" (2mm) of snow. In Pendleton, during the entire year, snow falls for 17.5 days and aggregates up to 9.41" (239mm) of snow.

Daylight

In September, the average length of the day is 12h and 31min.
On the first day of September, sunrise is at 6:17 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:53 am and sunset at 6:36 pm PDT.

Sunshine

In September, the average sunshine is 10.6h.

UV index

In Pendleton, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for average individuals.
Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Preventative actions are necessary - The mandate to avoid skin and eye damage is in place. When the Sun's UV radiation is most intense during midday, it's best to find shade and limit exposure. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage. On your guard! Snow's reflection can almost double the intensity of the Sun's UV radiation.
Updated: Jul 17, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Pendleton in September?

The average high-temperature and low-temperature during September are 74.1°F (23.4°C) and 54.7°F (12.6°C) respectively.

What is the average humidity in September?

In Pendleton, the average relative humidity in September is 46%.

How many days does it rain in September?

In Pendleton, during September, the rain falls for 7 days and regularly aggregates up to 0.51" (13mm) of precipitation.

When does it start snowing?

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

What is the average length of the day in September?

The average day length in September is 12h and 31min.

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:17 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:53 am and sunset at 6:36 pm PDT.

How long on average sun shines in September?

In Pendleton, the average sunshine duration in September is 10.6h.

What is the UV index reading in September?

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a medium hazard to health 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
Pendleton, OR

Average temperature in September - Pendleton, OR
  • Average high temperature in September: 74.1°F

The warmest month (with the highest average high temperature) is July (84.4°F).
The month with the lowest average high temperature is December (37.9°F).

  • Average low temperature in September: 54.7°F

The month with the highest average low temperature is August (61.7°F).
The coldest month (with the lowest average low temperature) is December (27.3°F).

Average pressure in September
Pendleton, OR

Average pressure in September - Pendleton, OR
  • Average pressure in September: 29.96"Hg

The month with the highest atmospheric pressure is January (30.2"Hg).
The month with the lowest atmospheric pressure is August (29.91"Hg).

Average wind speed in September
Pendleton, OR

Average wind speed in September - Pendleton, OR
  • Average wind speed in September: 6.2mph

The windiest month (with the highest average wind speed) is April (8.3mph).
The calmest month (with the lowest average wind speed) is September (6.2mph).

Average humidity in September
Pendleton, OR

Average humidity in September - Pendleton, OR
  • Average humidity in September: 46%

The month with the highest relative humidity is January (79%).
The month with the lowest relative humidity is August (38%).

Average rainfall in September
Pendleton, OR

Average rainfall in September - Pendleton, OR
  • Average rainfall in September: 0.51"

The wettest month (with the highest rainfall) is March (1.65").
The driest month (with the least rainfall) is July (0.24").

Average rainfall days in September
Pendleton, OR

Average rainfall days in September - Pendleton, OR
  • Average rainfall days in September: 7 days

The month with the highest number of rainy days is March (17.1 days).
The month with the least rainy days is August (3.6 days).

Average snowfall in September
Pendleton, OR

Average snowfall in September - Pendleton, OR
  • Average snowfall in September: 0.08"

The month with the highest snowfall is February (3.62").
The months with the least snowfall are May, June, July, August and October (0").

Average snowfall days in September
Pendleton, OR

Average snowfall days in September - Pendleton, OR
  • Average snowfall days in September: 0.1 days

The month with the highest number of snowfall days is December (5.5 days).
The months with the least snowfall days are May, June, July, August and October (0 days).

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

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

The month with the longest days is June (Average daylight: 15h and 36min).
The month with the shortest days is December (Average daylight: 8h and 48min).

  • Average sunshine in September: 10h and 4min

The months with the most sunshine are July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are January and December (Average sunshine: 5h and 24min).

Average sunshine days in September
Pendleton, OR

Average sunshine days in September - Pendleton, OR
  • Average sunshine days in September: 21.1 days

The month with the most sunshine days is July (24.4 days).
The month with the least sunshine days is March (11.7 days).

Average UV index in September
Pendleton, OR

Average UV index in September - Pendleton, OR
  • 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 January, February, November and December (UV index 2).

Average cloud cover in September
Pendleton, OR

Average cloud cover in September - Pendleton, OR
  • Average cloud cover in September: 16

The month with the most cloud cover is February (Cloud cover 44).
The month with the least cloud cover is August (Cloud cover 9).

Average visibility in September
Pendleton, OR

Average visibility in September - Pendleton, OR
  • Average visibility in September: 6mi

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

Pendleton, Oregon, USA

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