September weather forecastPrineville, OR
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Prineville, Oregon, with an average temperature fluctuating between 47.5°F (8.6°C) and 70.9°F (21.6°C).Temperature
As August shifts into September, a slight alteration in temperatures is observed, with average highs reducing from a moderately hot 81°F (27.2°C) to an agreeable 70.9°F (21.6°C). The anticipated average low-temperature for September, a chilly 47.5°F (8.6°C), shows a substantial deviation from the daytime maximums.Humidity
The average relative humidity in September is 52%.Rainfall
In Prineville, in September, during 6.6 rainfall days, 0.71" (18mm) of precipitation is typically accumulated. In Prineville, during the entire year, the rain falls for 138.8 days and collects up to 14.69" (373mm) of precipitation.Snowfall
Months with snowfall are January through May, September through December. September is the first month it typically snows. Throughout September, in the average 0.3 snowfall days, it receives 0.12" (3mm) of snow. In Prineville, during the entire year, snow falls for 53.7 days and aggregates up to 25" (635mm) of snow.Daylight
The average length of the day in September is 12h and 30min.On the first day of September, sunrise is at 6:27 am and sunset at 7:38 pm. On the last day of the month, sunrise is at 7:00 am and sunset at 6:45 pm PDT.
Sunshine
In September, the average sunshine is 10.9h.UV index
In September, the average daily maximum UV index is 3. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the ordinary person.Note: A maximum daily UV index of 3 during September morphs into the following directions:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. The most potent solar radiation is around mid-day, so one should minimize exposure to direct sunlight during this period. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Prineville, OR
- Average high temperature in September: 70.9°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 (36.5°F).
- Average low temperature in September: 47.5°F
The month with the highest average low temperature is August (52.9°F).
The coldest month (with the lowest average low temperature) is December (25°F).
Average pressure in September
Prineville, 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
Prineville, OR
- Average wind speed in September: 5.4mph
The windiest months (with the highest average wind speed) are March and April (7.1mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).
Average humidity in September
Prineville, OR
- Average humidity in September: 52%
The month with the highest relative humidity is December (81%).
The months with the lowest relative humidity are July and August (45%).
Average rainfall in September
Prineville, OR
- Average rainfall in September: 0.71"
The wettest month (with the highest rainfall) is December (1.89").
The driest month (with the least rainfall) is July (0.31").
Average rainfall days in September
Prineville, OR
- Average rainfall days in September: 6.6 days
The month with the highest number of rainy days is March (17.5 days).
The month with the least rainy days is July (4.2 days).
Average snowfall in September
Prineville, OR
- Average snowfall in September: 0.12"
The month with the highest snowfall is February (6.54").
The months with the least snowfall are June, July and August (0").
Average snowfall days in September
Prineville, OR
- Average snowfall days in September: 0.3 days
The month with the highest number of snowfall days is December (13.3 days).
The months with the least snowfall days are June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Prineville, OR
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).
- Average sunshine in September: 10h and 54min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 5h and 18min).
Average sunshine days in September
Prineville, OR
- Average sunshine days in September: 20.9 days
The month with the most sunshine days is July (24.8 days).
The month with the least sunshine days is March (8.8 days).
Average UV index in September
Prineville, 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
Prineville, OR
- Average cloud cover in September: 17
The month with the most cloud cover is December (Cloud cover 47).
The months with the least cloud cover are July and August (Cloud cover 10).
Average visibility in September
Prineville, OR
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (5mi).
