September weather forecastDiamond Lake, OR
September
Weather in September
The first month of the autumn, September, is also an agreeable month in Diamond Lake, Oregon, with an average temperature varying between 41.9°F (5.5°C) and 68.4°F (20.2°C).Temperature
The beginning of September brings a minor change in the average high-temperature, shifting from a moderately hot 76.5°F (24.7°C) in August to a pleasant 68.4°F (20.2°C). Diamond Lake reports a considerable drop from daytime temperatures in September, recording an average nighttime figure of 41.9°F (5.5°C).Humidity
In Diamond Lake, the average relative humidity in September is 63%.Rainfall
In September, the rain falls for 7.3 days. Throughout September, 1.18" (30mm) of precipitation is accumulated. In Diamond Lake, during the entire year, the rain falls for 105.2 days and collects up to 35.83" (910mm) of precipitation.Snowfall
Months with snowfall are January through June, September through December. September is the first month it typically snows. Throughout September, in the average 1.7 snowfall days, it receives 1.65" (42mm) of snow. Throughout the year, there are 133.8 snowfall days, and 206.73" (5251mm) of snow is accumulated.Daylight
In Diamond Lake, the average length of the day in September is 12h and 29min.On the first day of September, sunrise is at 6:33 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:05 am and sunset at 6:50 pm PDT.
Sunshine
In September, the average sunshine is 10.4h.UV index
In September, the average daily maximum UV index is 3. 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 daily UV index of 3 in September interprets into the following recommendations:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes. Be careful! The Sun's UV radiation can nearly be doubled by the reflective quality of snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Diamond Lake, OR
- Average high temperature in September: 68.4°F
The warmest months (with the highest average high temperature) are July and August (76.5°F).
The month with the lowest average high temperature is December (35.4°F).
- Average low temperature in September: 41.9°F
The month with the highest average low temperature is August (46.4°F).
The coldest month (with the lowest average low temperature) is December (23.5°F).
Average pressure in September
Diamond Lake, OR
- Average pressure in September: 30"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is August (29.98"Hg).
Average wind speed in September
Diamond Lake, OR
- Average wind speed in September: 4.5mph
The windiest month (with the highest average wind speed) is January (6mph).
The calmest month (with the lowest average wind speed) is August (4.3mph).
Average humidity in September
Diamond Lake, OR
- Average humidity in September: 63%
The months with the highest relative humidity are February and March (88%).
The months with the lowest relative humidity are July and August (59%).
Average rainfall in September
Diamond Lake, OR
- Average rainfall in September: 1.18"
The wettest month (with the highest rainfall) is January (5.55").
The driest month (with the least rainfall) is July (0.39").
Average rainfall days in September
Diamond Lake, OR
- Average rainfall days in September: 7.3 days
The month with the highest number of rainy days is May (14.3 days).
The month with the least rainy days is July (4.6 days).
Average snowfall in September
Diamond Lake, OR
- Average snowfall in September: 1.65"
The months with the highest snowfall are January and December (39.21").
The months with the least snowfall are July and August (0").
Average snowfall days in September
Diamond Lake, OR
- Average snowfall days in September: 1.7 days
The month with the highest number of snowfall days is March (21.8 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in September /
Average sunshine in September
Diamond Lake, OR
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in September: 10h and 24min
The month with the most sunshine is July (Average sunshine: 11h and 54min).
The months with the least sunshine are January and December (Average sunshine: 4h and 30min).
Average sunshine days in September
Diamond Lake, OR
- Average sunshine days in September: 19.7 days
The month with the most sunshine days is July (23.6 days).
The month with the least sunshine days is March (7.4 days).
Average UV index in September
Diamond Lake, OR
- Average UV index in September: 3
The month with the highest UV index is July (UV index 5).
The month with the lowest UV index is February (UV index 1).
Average cloud cover in September
Diamond Lake, OR
- Average cloud cover in September: 25
The month with the most cloud cover is March (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 14).
Average visibility in September
Diamond Lake, 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, November and December (4mi).





