September weather forecastScappoose, OR
September
Weather in September
September, the first month of the autumn in Scappoose, is still a pleasant month, with an average temperature varying between 72.3°F (22.4°C) and 49.8°F (9.9°C).Temperature
The shift from August to September includes a small decrease in the average high-temperature, from a warm 79.7°F (26.5°C) to an agreeable 72.3°F (22.4°C). Scappoose registers a pronounced decline from daytime peak temperatures, averaging a chilly 49.8°F (9.9°C) lows in September.Humidity
In September, the average relative humidity is 74%.Rainfall
In Scappoose, in September, during 11.5 rainfall days, 1.81" (46mm) of precipitation is typically accumulated. Throughout the year, there are 181.3 rainfall days, and 35.55" (903mm) of precipitation is accumulated.Snowfall
In Scappoose, snow does not fall in April through October.Daylight
The average length of the day in September is 12h and 31min.On the first day of September, 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 9h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 4 during September translates into these guidelines:
Be vigilant - Preventing sunburn is recommended. Avoiding direct sunlight during midday hours helps reduce the risk from intense UV radiation. Sun protection is enhanced with clothing that boasts a tight weave yet offers a loose fit.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Scappoose, OR
- Average high temperature in September: 72.3°F
The warmest month (with the highest average high temperature) is August (79.7°F).
The month with the lowest average high temperature is December (42.8°F).
- Average low temperature in September: 49.8°F
The month with the highest average low temperature is August (52.9°F).
The coldest month (with the lowest average low temperature) is December (33.1°F).
Average pressure in September
Scappoose, 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
Scappoose, OR
- Average wind speed in September: 4mph
The windiest month (with the highest average wind speed) is March (4.8mph).
The calmest month (with the lowest average wind speed) is September (4mph).
Average humidity in September
Scappoose, OR
- Average humidity in September: 74%
The months with the highest relative humidity are February and November (87%).
The months with the lowest relative humidity are July and August (69%).
Average rainfall in September
Scappoose, OR
- Average rainfall in September: 1.81"
The wettest month (with the highest rainfall) is January (5.24").
The driest month (with the least rainfall) is August (0.43").
Average rainfall days in September
Scappoose, OR
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is March (21.1 days).
The months with the least rainy days are July and August (5.5 days).
Average snowfall in September
Scappoose, OR
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.77").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Scappoose, OR
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.1 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
Scappoose, OR
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 42min).
The month with the shortest days is December (Average daylight: 8h and 42min).
- Average sunshine in September: 9h and 0min
The month with the most sunshine is August (Average sunshine: 10h and 42min).
The months with the least sunshine are January and February (Average sunshine: 3h and 48min).
Average sunshine days in September
Scappoose, OR
- Average sunshine days in September: 16.5 days
The month with the most sunshine days is July (23.2 days).
The month with the least sunshine days is February (7.8 days).
Average UV index in September
Scappoose, 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
Scappoose, OR
- Average cloud cover in September: 37
The month with the most cloud cover is February (Cloud cover 62).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Scappoose, OR
- Average visibility in September: 5mi
The month with the highest visibility is August (6mi).
The months with the lowest visibility are January, February, March, November and December (4mi).





