September weather forecastOregon City, OR
September
Weather in September
The onset of autumn in September brings with it a gradual coolness to the weather in Oregon City. The cityscape takes on a palette of warm hues while shorter daylight hours hint towards the forthcoming winter. Worth mentioning is the drastic drop in daytime high temperatures to 73.6°F (23.1°C) which heralds cooler days ahead. The weather during this month strikes a balance between the disappearing warmth and the approaching chill. As the month ends, the cool morning aroma laden with dew foretells the changing climate.Temperature
September in Oregon City brings a slight decrease in the average high-temperature, shifting from 81.1°F (27.3°C) in August to a still warm 73.6°F (23.1°C). Oregon City reports a sharp reduction in temperature during September, averaging at a cool 50.5°F (10.3°C) at night.Humidity
In Oregon City, the average relative humidity in September is 69%.Rainfall
In Oregon City, during September, the rain falls for 9.5 days and regularly aggregates up to 1.5" (38mm) of precipitation. In Oregon City, during the entire year, the rain falls for 169.9 days and collects up to 32.76" (832mm) of precipitation.Snowfall
In Oregon City, snow does not fall in April through October.Daylight
In Oregon City, the average length of the day in September is 12h and 31min.On the first day of the month, sunrise is at 6:33 am and sunset at 7:47 pm. On the last day of September, sunrise is at 7:08 am and sunset at 6:51 pm PDT.
Sunshine
In Oregon City, the average sunshine in September is 9.4h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: The UV index of 4 in September translates into these instructions:
Prioritize safety - The need to safeguard skin and eyes from harm is emphasized. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Oregon City, OR
- Average high temperature in September: 73.6°F
The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (44.4°F).
- Average low temperature in September: 50.5°F
The month with the highest average low temperature is August (54°F).
The coldest month (with the lowest average low temperature) is December (34.3°F).
Average pressure in September
Oregon City, 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
Oregon City, OR
- Average wind speed in September: 3.9mph
The windiest month (with the highest average wind speed) is January (6mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).
Average humidity in September
Oregon City, OR
- Average humidity in September: 69%
The month with the highest relative humidity is February (84%).
The month with the lowest relative humidity is August (64%).
Average rainfall in September
Oregon City, OR
- Average rainfall in September: 1.5"
The wettest month (with the highest rainfall) is December (5.16").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in September
Oregon City, OR
- Average rainfall days in September: 9.5 days
The month with the highest number of rainy days is March (20.3 days).
The month with the least rainy days is August (4 days).
Average snowfall in September
Oregon City, OR
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.5").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Oregon City, 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 April, May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Oregon City, 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 24min
The month with the most sunshine is August (Average sunshine: 11h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 18min).
Average sunshine days in September
Oregon City, OR
- Average sunshine days in September: 19 days
The month with the most sunshine days is July (26.2 days).
The month with the least sunshine days is February (8.1 days).
Average UV index in September
Oregon City, 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
Oregon City, OR
- Average cloud cover in September: 32
The month with the most cloud cover is February (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 22).
Average visibility in September
Oregon City, OR
- Average visibility in September: 6mi
The months with the highest visibility are July, August, September and October (6mi).
The months with the lowest visibility are January, February, March, April, May, June, November and December (5mi).
