Contents
- 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
Weather in September
Temperature
The transition into September is accompanied by a slight temperature decrease, with the average high-temperature shifting from a warm 81.5°F (27.5°C) in August to a still moderately hot 74.1°F (23.4°C). Portland experiences a substantial decline from the daytime high temperatures in September, settling on an average low of 51.3°F (10.7°C).Humidity
In September, the average relative humidity in Portland is 69%.Rainfall
In Portland, during September, the rain falls for 10.4 days and regularly aggregates up to 1.69" (43mm) of precipitation. In Portland, during the entire year, the rain falls for 173.1 days and collects up to 31.18" (792mm) of precipitation.Snowfall
April through October are months without snowfall in Portland, Oregon.Daylight
The average length of the day in September is 12h and 31min.On the first day of September in Portland, Oregon, sunrise is at 6:33 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:52 pm PDT.
Sunshine
In September, the average sunshine is 9.3h.UV index
In Portland, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: During September, 4 as the daily maximum UV index converts into the following advice:
Guard yourself - Avoiding sunburn is suggested. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
Frequently asked questions
What is the average September temperature in Portland?
What is the average humidity in September in Portland?
How many days does it rain in September in Portland?
When it does not snow in Portland?
What is the average length of the day in September in Portland?
When is the sunrise / sunset in September in Portland?
How many hours of sunshine does Portland have in September?
What is the UV index intensity in September in Portland?
Average temperature in September
Portland, OR
- Average high temperature in September: 74.1°F
The warmest month (with the highest average high temperature) is August (81.5°F).
The month with the lowest average high temperature is December (44.1°F).
- Average low temperature in September: 51.3°F
The month with the highest average low temperature is August (55°F).
The coldest month (with the lowest average low temperature) is December (34.7°F).
Average pressure in September
Portland, 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).
Average wind speed in September
Portland, OR
- Average wind speed in September: 4mph
The windiest month (with the highest average wind speed) is January (5.8mph).
The calmest month (with the lowest average wind speed) is August (3.9mph).
Average humidity in September
Portland, OR
- Average humidity in September: 69%
The months with the highest relative humidity are January, February and December (83%).
The month with the lowest relative humidity is August (63%).
Average rainfall in September
Portland, OR
- Average rainfall in September: 1.69"
The wettest month (with the highest rainfall) is December (4.53").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in September
Portland, OR
- Average rainfall days in September: 10.4 days
The month with the highest number of rainy days is March (20.4 days).
The month with the least rainy days is July (4.9 days).
Average snowfall in September
Portland, OR
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.5").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Portland, OR
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Portland, 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 2min
The month with the most sunshine is August (Average sunshine: 10h and 54min).
The month with the least sunshine is January (Average sunshine: 4h and 6min).
Average sunshine days in September
Portland, OR
- Average sunshine days in September: 17.4 days
The months with the most sunshine days are July and August (23.8 days).
The month with the least sunshine days is March (8.3 days).
Average UV index in September
Portland, 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
Portland, OR
- Average cloud cover in September: 33
The month with the most cloud cover is February (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 23).
Average visibility in September
Portland, 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).
Portland, Oregon, USA
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