September weather forecastBrothers, OR
September
Weather in September
September, the first month of the autumn in Brothers, is still a pleasant month, with temperature in the range of an average high of 71.1°F (21.7°C) and an average low of 48.4°F (9.1°C).Temperature
Start of September brings a shift in the average high-temperature, falling from August's moderately hot 80.6°F (27°C) to a pleasant 71.1°F (21.7°C). Brothers sees a large disparity in day to night temperatures in September, with the night temperature dropping to an average of 48.4°F (9.1°C).Humidity
In Brothers, the average relative humidity in September is 50%.Rainfall
In Brothers, in September, it is raining for 3.7 days, with typically 0.35" (9mm) of accumulated precipitation. Throughout the year, in Brothers, Oregon, there are 65.5 rainfall days, and 5.67" (144mm) of precipitation is accumulated.Snowfall
Months with snowfall in Brothers are January through April, September through December. September is the first month it typically snows. Throughout September, in the average 0.2 snowfall days, it receives 0.04" (1mm) of snow. Throughout the year, in Brothers, there are 20.9 snowfall days, and 9.02" (229mm) of snow is accumulated.Daylight
The average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:26 am and sunset at 7:37 pm. On the last day of September, sunrise is at 6:59 am and sunset at 6:44 pm PDT.
Sunshine
The average sunshine in September is 11h.UV index
In September, the average daily maximum UV index is 3. A UV Index estimate of 3 to 5 represents a medium health hazard from unsafe exposure to UV radiation for the average person.Note: In September, the UV index of 3 transforms into the following advice:
Prioritize safety - The need to safeguard skin and eyes from harm is emphasized. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Alert! The snow's reflection can amplify the UV radiation of the Sun nearly twice.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Brothers, OR
- Average high temperature in September: 71.1°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is December (36.1°F).
- Average low temperature in September: 48.4°F
The month with the highest average low temperature is August (54.3°F).
The coldest month (with the lowest average low temperature) is December (24.3°F).
Average pressure in September
Brothers, OR
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.19"Hg).
The month with the lowest atmospheric pressure is August (29.96"Hg).
Average wind speed in September
Brothers, OR
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is March (7.6mph).
The calmest months (with the lowest average wind speed) are August and September (5.7mph).
Average humidity in September
Brothers, OR
- Average humidity in September: 50%
The month with the highest relative humidity is December (81%).
The months with the lowest relative humidity are July and August (43%).
Average rainfall in September
Brothers, OR
- Average rainfall in September: 0.35"
The wettest month (with the highest rainfall) is May (0.67").
The driest month (with the least rainfall) is July (0.08").
Average rainfall days in September
Brothers, OR
- Average rainfall days in September: 3.7 days
The month with the highest number of rainy days is March (9 days).
The month with the least rainy days is July (2 days).
Average snowfall in September
Brothers, OR
- Average snowfall in September: 0.04"
The month with the highest snowfall is February (3.15").
The months with the least snowfall are May, June, July and August (0").
Average snowfall days in September
Brothers, OR
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is December (4.8 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Brothers, OR
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).
- Average sunshine in September: 11h and 0min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 24min).
Average sunshine days in September
Brothers, OR
- Average sunshine days in September: 25.8 days
The month with the most sunshine days is July (28.3 days).
The month with the least sunshine days is March (19.5 days).
Average UV index in September
Brothers, OR
- Average UV index in September: 3
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Brothers, OR
- Average cloud cover in September: 16
The month with the most cloud cover is December (Cloud cover 45).
The months with the least cloud cover are July and August (Cloud cover 9).
Average visibility in September
Brothers, OR
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October and November (6mi).
The month with the lowest visibility is December (5mi).





