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 commencement of September indicates a shift in the average high-temperature, receding from August's moderately hot 81.9°F (27.7°C) to an agreeable 72.3°F (22.4°C). In September, the temperature in Riley, Oregon, drops to an average of 51.1°F (10.6°C) at night.Humidity
In September, the average relative humidity is 40%.Rainfall
In Riley, in September, during 5.2 rainfall days, 0.47" (12mm) of precipitation is typically accumulated. Throughout the year, in Riley, there are 125.1 rainfall days, and 11.26" (286mm) of precipitation is accumulated.Snowfall
In Riley, snow does not fall in April through October.Daylight
The average length of the day in September is 12h and 29min.On the first day of September, sunrise is at 6:22 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:55 am and sunset at 6:40 pm PDT.
Sunshine
In Riley, the average sunshine in September is 10.9h.UV index
The average daily maximum UV index in September in Riley is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for average individuals.Note: The maximum daily UV index, 4 in September, converts into the following recommendations:
Act with care - Obligation to protect against skin and eye damage is highlighted. Protect yourself from the midday Sun's peak UV radiation by minimizing exposure. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Frequently asked questions
What is the temperature in September in Riley?
What is the average humidity in September in Riley?
How much does it rain in Riley in September?
When it does not snow in Riley?
How many hours of daylight does Riley have in September?
What time are sunrise and sunset in September in Riley?
How many hours of sunshine does Riley have in September?
What is the UV index intensity in September in Riley?
Average temperature in September
Riley, OR
- Average high temperature in September: 72.3°F
The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is December (33.1°F).
- Average low temperature in September: 51.1°F
The month with the highest average low temperature is August (58.1°F).
The coldest month (with the lowest average low temperature) is December (21.2°F).
Average pressure in September
Riley, OR
- Average pressure in September: 29.98"Hg
The month with the highest atmospheric pressure is January (30.22"Hg).
The month with the lowest atmospheric pressure is August (29.94"Hg).
Average wind speed in September
Riley, OR
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is April (9.9mph).
The calmest month (with the lowest average wind speed) is August (7.5mph).
Average humidity in September
Riley, OR
- Average humidity in September: 40%
The month with the highest relative humidity is December (83%).
The months with the lowest relative humidity are July and August (33%).
Average rainfall in September
Riley, OR
- Average rainfall in September: 0.47"
The wettest month (with the highest rainfall) is December (1.54").
The driest month (with the least rainfall) is July (0.16").
Average rainfall days in September
Riley, OR
- Average rainfall days in September: 5.2 days
The month with the highest number of rainy days is March (17.7 days).
The month with the least rainy days is August (3.3 days).
Average snowfall in September
Riley, OR
- Average snowfall in September: 0"
The month with the highest snowfall is December (0.87").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Riley, OR
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is December (3.1 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
Riley, OR
- Average daylight in September: 12h and 3min
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: 10h and 5min
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 12min).
Average sunshine days in September
Riley, OR
- Average sunshine days in September: 22.9 days
The months with the most sunshine days are July and August (25.3 days).
The month with the least sunshine days is March (11.5 days).
Average UV index in September
Riley, OR
- Average UV index in September: 4
The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Riley, OR
- Average cloud cover in September: 14
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 9).
Average visibility in September
Riley, OR
- Average visibility in September: 6mi
The months with the highest visibility are February, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is January (5mi).
Riley, Oregon, USA
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