September weather forecastBeaverton, OR
September
Weather in September
The transitional month of September slows down the pace of summer and inches towards autumn. The dry spell finally ends with a significant increase in precipitation to 1.54" (39mm). Warmer temperatures persist, but with a trend of gradual cooling. Hours of daylight start to decline, hinting at the forthcoming fall season. The September weather paints Beaverton in brilliant hues of yellow and brown.Temperature
The arrival of September correlates with a minor temperature reduction, down from August's warm 81.7°F (27.6°C) to a still moderately hot 74.3°F (23.5°C). Despite a significant disparity with daytime temperatures, an average low-temperature of 52°F (11.1°C) is recorded during September.Humidity
The average relative humidity in September is 69%.Rainfall
In Beaverton, Oregon, in September, during 10.5 rainfall days, 1.54" (39mm) of precipitation is typically accumulated. In Beaverton, Oregon, during the entire year, the rain falls for 173.2 days and collects up to 30.55" (776mm) of precipitation.Snowfall
In Beaverton, snow does not fall in April through October.Daylight
In Beaverton, 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
The average sunshine in September is 9.2h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the average person.Note: The average daily UV index of 4 in September transforms into the following instructions:
Take precautions - Protection against sunburn is recommended. Avoiding the Sun during its peak radiation time around midday is a healthy practice. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Beaverton, 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
Beaverton, 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
Beaverton, 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
Beaverton, 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
Beaverton, 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
Beaverton, 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
Beaverton, 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
Beaverton, 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
Beaverton, OR
- Average daylight in September: 12h and 30min
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 12min
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
Beaverton, 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
Beaverton, 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
Beaverton, 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
Beaverton, 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).
