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 shift from August to September coincides with a small decrease in the average high-temperature, down to a still moderately hot 73.6°F (23.1°C) from 81.1°F (27.3°C). Despite soaring daytime temperatures, Clackamas registers a consistent average low-temperature of 50.5°F (10.3°C) in September.Humidity
In September, the average relative humidity is 69%.Rainfall
In Clackamas, Oregon, in September, it is raining for 9.5 days, with typically 1.5" (38mm) of accumulated precipitation. Throughout the year, there are 169.9 rainfall days, and 32.76" (832mm) of precipitation is accumulated.Snowfall
In Clackamas, 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 6:32 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:08 am and sunset at 6:51 pm PDT.
Sunshine
The average sunshine in September is 9.4h.UV index
In Clackamas, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the average person.Note: The UV index of 4 in September translates into these instructions:
Heed the precautions - Protecting the skin and eyes from damage is compulsory. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow in Clackamas?
How many hours of daylight does Clackamas have in September?
When is the sunrise / sunset in September in Clackamas?
How long on average sun shines in September?
How high is the UV index in September?
Average temperature in September
Clackamas, 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
Clackamas, 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
Clackamas, 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
Clackamas, 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
Clackamas, 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
Clackamas, 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
Clackamas, 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
Clackamas, 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
Clackamas, 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: 11h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 18min).
Average sunshine days in September
Clackamas, 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
Clackamas, 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
Clackamas, 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
Clackamas, 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).
Clackamas, Oregon, USA
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