September weather forecast
Cedar Mill, OR

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Weather in September

September, the first month of the autumn in Cedar Mill, is also a moderately hot month, with temperature in the range of an average low of 52°F (11.1°C) and an average high of 74.3°F (23.5°C).

Temperature

A mild shift in the average high-temperature occurs in September, reducing from a moderately hot 81.7°F (27.6°C) in August to a still warm 74.3°F (23.5°C). Cedar Mill endures a clear shift from daytime heat to a mean low-temperature of 52°F (11.1°C) during September nights.

Humidity

In Cedar Mill, the average relative humidity in September is 69%.

Rainfall

In Cedar Mill, in September, during 10.5 rainfall days, 1.54" (39mm) of precipitation is typically accumulated. In Cedar Mill, Oregon, during the entire year, the rain falls for 173.2 days and collects up to 30.55" (776mm) of precipitation.

Snowfall

April through October are months without snowfall.

Daylight

The average length of the day in September is 12h and 31min.
On the first day of September in Cedar Mill, sunrise is at 6:33 am and sunset at 7:48 pm. On the last day of the month, sunrise is at 7:09 am and sunset at 6:52 pm PDT.

Sunshine

In September, the average sunshine is 9.2h.

UV index

In Cedar Mill, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the ordinary person.
Note: A maximum UV index of 4 in September translates into the following recommendations:
Prioritize safety - Suggestions to prevent sun damage are offered. Midday is the peak time for the Sun's radiation; stay in the shade and protect yourself. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Updated: Aug 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the average September temperature?

September temperatures in Cedar Mill vary between a high-temperature of 74.3°F (23.5°C) and a low-temperature of 52°F (11.1°C). In August, the average heat index (a.k.a. 'felt air temperature', 'real feel'), which combines air temperature and relative humidity, is calculated to be 84.2°F (29°C).

What is the average humidity in September?

In Cedar Mill, the average relative humidity in September is 69%.

How many days does it rain in September?

In Cedar Mill, during September, the rain falls for 10.5 days and regularly aggregates up to 1.54" (39mm) of precipitation.

When it does not snow?

In Cedar Mill, snow does not fall in April through October.

How many hours of daylight does Cedar Mill have in September?

In September, the average day length is 12h and 31min.

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:33 am and sunset at 7:48 pm. On the last day of the month, sunrise is at 7:09 am and sunset at 6:52 pm PDT.

How many hours of sunshine does Cedar Mill have in September?

In September, the average sunshine duration is 9.2h.

What is the UV index intensity in September?

In Cedar Mill, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health threat 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
Cedar Mill, OR

Average temperature in September - Cedar Mill, OR
  • Average high temperature in September: 74.3°F

The warmest month (with the highest average high temperature) is August (81.7°F).
The month with the lowest average high temperature is December (44.2°F).

  • Average low temperature in September: 52°F

The month with the highest average low temperature is August (55.6°F).
The coldest month (with the lowest average low temperature) is December (34.7°F).

Average pressure in September
Cedar Mill, OR

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

The month with the highest atmospheric pressure is January (30.11"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).

Average wind speed in September
Cedar Mill, OR

Average wind speed in September - Cedar Mill, OR
  • Average wind speed in September: 4.1mph

The windiest month (with the highest average wind speed) is January (5.4mph).
The calmest month (with the lowest average wind speed) is August (4mph).

Average humidity in September
Cedar Mill, OR

Average humidity in September - Cedar Mill, OR
  • Average humidity in September: 69%

The months with the highest relative humidity are February and December (84%).
The month with the lowest relative humidity is August (63%).

Average rainfall in September
Cedar Mill, OR

Average rainfall in September - Cedar Mill, OR
  • Average rainfall in September: 1.54"

The wettest month (with the highest rainfall) is December (4.61").
The driest month (with the least rainfall) is July (0.31").

Average rainfall days in September
Cedar Mill, OR

Average rainfall days in September - Cedar Mill, OR
  • Average rainfall days in September: 10.5 days

The month with the highest number of rainy days is March (20.6 days).
The month with the least rainy days is August (4.6 days).

Average snowfall in September
Cedar Mill, OR

Average snowfall in September - Cedar Mill, OR
  • Average snowfall in September: 0"

The month with the highest snowfall is February (1.61").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in September
Cedar Mill, OR

Average snowfall days in September - Cedar Mill, OR
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (2.2 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Cedar Mill, OR

Average daylight in September / Average sunshine in September - Cedar Mill, 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: 9h and 1min

The month with the most sunshine is August (Average sunshine: 10h and 54min).
The month with the least sunshine is February (Average sunshine: 3h and 54min).

Average sunshine days in September
Cedar Mill, OR

Average sunshine days in September - Cedar Mill, OR
  • Average sunshine days in September: 17.9 days

The month with the most sunshine days is July (24.9 days).
The month with the least sunshine days is March (8.6 days).

Average UV index in September
Cedar Mill, OR

Average UV index in September - Cedar Mill, OR
  • Average UV index in September: 4

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in September
Cedar Mill, OR

Average cloud cover in September - Cedar Mill, OR
  • Average cloud cover in September: 33

The month with the most cloud cover is February (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 23).

Average visibility in September
Cedar Mill, OR

Average visibility in September - Cedar Mill, OR
  • Average visibility in September: 6mi

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

Cedar Mill, Oregon, USA

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