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 start of September involves a subtle temperature drop, shifting from 81.1°F (27.3°C) in August to a still warm 74.5°F (23.6°C). Riddle marks a considerable descent from the daytime apex, as the average temperature dips to a frosty 44.8°F (7.1°C) at night throughout September.Humidity
In September, the average relative humidity is 72%.Rainfall
In September, the rain falls for 3.6 days. Throughout September, 0.31" (8mm) of precipitation is accumulated. In Riddle, during the entire year, the rain falls for 93.9 days and collects up to 7.64" (194mm) of precipitation.Snowfall
In Riddle, snow does not fall in April through October.Daylight
In Riddle, the average length of the day in September is 12h and 29min.On the first day of the month, sunrise is at 6:38 am and sunset at 7:47 pm. On the last day of September, sunrise is at 7:10 am and sunset at 6:55 pm PDT.
Sunshine
The average sunshine in September is 9.7h.UV index
The average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the average person.Note: The daily high UV index of 3 during September translates into the following recommendations:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. Around midday, solar radiation is most harmful; hence, exposure should be limited. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are September temperatures?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
How many hours of daylight does Riddle have in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Riddle, OR
- Average high temperature in September: 74.5°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 (45.7°F).
- Average low temperature in September: 44.8°F
The month with the highest average low temperature is August (47.7°F).
The coldest month (with the lowest average low temperature) is December (32.2°F).
Average pressure in September
Riddle, 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
Riddle, OR
- Average wind speed in September: 3.2mph
The windiest month (with the highest average wind speed) is January (4.1mph).
The calmest month (with the lowest average wind speed) is September (3.2mph).
Average humidity in September
Riddle, OR
- Average humidity in September: 72%
The months with the highest relative humidity are January, February and December (86%).
The month with the lowest relative humidity is August (69%).
Average rainfall in September
Riddle, OR
- Average rainfall in September: 0.31"
The wettest months (with the highest rainfall) are January, February and December (1.1").
The driest months (with the least rainfall) are July and August (0.16").
Average rainfall days in September
Riddle, OR
- Average rainfall days in September: 3.6 days
The month with the highest number of rainy days is March (12.6 days).
The month with the least rainy days is August (2.4 days).
Average snowfall in September
Riddle, OR
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.87").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Riddle, OR
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (1.5 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
Riddle, OR
- Average daylight in September: 12h and 3min
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: 9h and 4min
The month with the most sunshine is August (Average sunshine: 11h and 18min).
The month with the least sunshine is December (Average sunshine: 4h and 18min).
Average sunshine days in September
Riddle, OR
- Average sunshine days in September: 25.9 days
The month with the most sunshine days is August (26.5 days).
The month with the least sunshine days is March (16.1 days).
Average UV index in September
Riddle, 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, November and December (UV index 2).
Average cloud cover in September
Riddle, OR
- Average cloud cover in September: 31
The month with the most cloud cover is March (Cloud cover 60).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility in September
Riddle, OR
- Average visibility in September: 5mi
The months with the highest visibility are July, August and September (5mi).
The months with the lowest visibility are January, February, March, April, May, June, October, November and December (4mi).
Riddle, Oregon, USA
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