September weather forecast
Coos Bay, OR

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A unique sandy and rocky shore near a forest of pine trees in the Shore Acres State Park in Coos Bay, Oregon
A unique sandy and rocky shore near a forest of pine trees in the Shore Acres State Park in Coos Bay, Oregon

Weather in September

September brings Coos Bay into the comfortable clasp of autumn. Compared to the peak summer months, rainfall escalates a little to 1.1" (28mm), offering relief from the intense dryness. The wind carries whispers of the approaching change, gathering momentum. The shrinking daylight hours are coupled with thicker cloud cover, adding a cooling respite. September marks a moderate shift in the weather of Coos Bay, replacing the heat of summer with milder autumn breezes.

Temperature

In September, Coos Bay's weather conditions record an average high-temperature of a still refreshing 65.8°F (18.8°C), demonstrating little divergence from the preceding month. Coos Bay experiences an average nighttime temperature of 51.6°F (10.9°C) in the month of September.

Humidity

In Coos Bay, the average relative humidity in September is 82%.

Rainfall

In Coos Bay, in September, during 7.1 rainfall days, 1.1" (28mm) of precipitation is typically accumulated. Throughout the year, there are 153 rainfall days, and 33.5" (851mm) of precipitation is accumulated.

Snowfall

March through October and December are months without snowfall.

Daylight

In Coos Bay, the average length of the day in September is 12h and 29min.
On the first day of the month, sunrise is at 6:41 am and sunset at 7:51 pm. On the last day of September, sunrise is at 7:14 am and sunset at 6:59 pm PDT.

Sunshine

In Coos Bay, the average sunshine in September is 9.6h.

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 the ordinary person.
Note: A maximum UV index of 4 in September translates into the following recommendations:
Act with care - The suggestion to avoid sunburn is emphasized. Direct Sun exposure should be minimized especially during midday when radiation is most intense. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Updated: Aug 29, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature?

During September, Coos Bay experiences an average high-temperature of 65.8°F (18.8°C) and a low-temperature of 51.6°F (10.9°C).

What is the average humidity in September?

In September, the average relative humidity is 82%.

How many days does it rain in September?

In September, in Coos Bay, the rain falls for 7.1 days. Throughout September, 1.1" (28mm) of precipitation is accumulated.

When it does not snow?

In Coos Bay, snow does not fall in March through October and December.

How many hours of daylight does Coos Bay have in September?

In Coos Bay, the average day length in September is 12h and 29min.

When are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:41 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:14 am and sunset at 6:59 pm PDT.

How many hours of sunshine does Coos Bay have in September?

In September, the average sunshine duration is 9.6h.

What is the UV index intensity in September in Coos Bay?

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate vulnerability from unprotected exposure to UV radiation.
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
Coos Bay, OR

Average temperature in September - Coos Bay, OR
  • Average high temperature in September: 65.8°F

The warmest month (with the highest average high temperature) is August (66.9°F).
The month with the lowest average high temperature is December (49.1°F).

  • Average low temperature in September: 51.6°F

The month with the highest average low temperature is August (52.3°F).
The coldest months (with the lowest average low temperature) are February and December (41.7°F).

Average pressure in September
Coos Bay, OR

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

The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is September (30.01"Hg).

Average wind speed in September
Coos Bay, OR

Average wind speed in September - Coos Bay, OR
  • Average wind speed in September: 7.1mph

The windiest month (with the highest average wind speed) is March (9.1mph).
The calmest month (with the lowest average wind speed) is August (6.9mph).

Average humidity in September
Coos Bay, OR

Average humidity in September - Coos Bay, OR
  • Average humidity in September: 82%

The months with the highest relative humidity are February and August (84%).
The months with the lowest relative humidity are April and October (81%).

Average rainfall in September
Coos Bay, OR

Average rainfall in September - Coos Bay, OR
  • Average rainfall in September: 1.1"

The wettest month (with the highest rainfall) is December (5.87").
The driest month (with the least rainfall) is July (0.16").

Average rainfall days in September
Coos Bay, OR

Average rainfall days in September - Coos Bay, OR
  • Average rainfall days in September: 7.1 days

The month with the highest number of rainy days is March (19.2 days).
The month with the least rainy days is August (3.5 days).

Average snowfall in September
Coos Bay, OR

Average snowfall in September - Coos Bay, OR
  • Average snowfall in September: 0"

The month with the highest snowfall is February (0.2").
The months with the least snowfall are March, April, May, June, July, August, September, October and December (0").

Average snowfall days in September
Coos Bay, OR

Average snowfall days in September - Coos Bay, OR
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (0.3 days).
The months with the least snowfall days are March, April, May, June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Coos Bay, OR

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

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).

  • Average sunshine in September: 9h and 4min

The month with the most sunshine is July (Average sunshine: 10h and 48min).
The months with the least sunshine are January and February (Average sunshine: 4h and 24min).

Average sunshine days in September
Coos Bay, OR

Average sunshine days in September - Coos Bay, OR
  • Average sunshine days in September: 21.6 days

The month with the most sunshine days is July (25.7 days).
The month with the least sunshine days is February (9.7 days).

Average UV index in September
Coos Bay, OR

Average UV index in September - Coos Bay, OR
  • Average UV index in September: 4

The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are February and December (UV index 2).

Average cloud cover in September
Coos Bay, OR

Average cloud cover in September - Coos Bay, OR
  • Average cloud cover in September: 28

The month with the most cloud cover is February (Cloud cover 56).
The months with the least cloud cover are July and September (Cloud cover 28).

Average visibility in September
Coos Bay, OR

Average visibility in September - Coos Bay, OR
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).

Coos Bay, Oregon, USA

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