September weather forecastWilliams, OR
September
Weather in September
The first month of the autumn, September, is still a warm month in Williams, Oregon, with an average temperature fluctuating between 44.8°F (7.1°C) and 76.5°F (24.7°C).Temperature
Williams's progression into September involves a gentle drop in the average high-temperature, from 84.4°F (29.1°C) in August to a still moderately hot 76.5°F (24.7°C). Williams's September nights represent a significant downturn from the day's heat, with an average temperature of 44.8°F (7.1°C).Humidity
In September, the average relative humidity is 64%.Rainfall
In September, the rain falls for 4.4 days. Throughout September, 0.43" (11mm) of precipitation is accumulated. In Williams, during the entire year, the rain falls for 92.5 days and collects up to 12.09" (307mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In Williams, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:39 am and sunset at 7:46 pm. On the last day of September, sunrise is at 7:09 am and sunset at 6:55 pm PDT.
Sunshine
In Williams, Oregon, the average sunshine in September is 10.5h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: In September, a daily UV index of 4 turns into the following recommendations:
Make use of precautions - It is urged to ward off sun damage. Given the potency of the midday Sun's UV radiation, one should avoid prolonged exposure. 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
Average temperature in September
Williams, OR
- Average high temperature in September: 76.5°F
The warmest month (with the highest average high temperature) is August (84.4°F).
The month with the lowest average high temperature is December (43.5°F).
- Average low temperature in September: 44.8°F
The months with the highest average low temperature are July and August (49.5°F).
The coldest month (with the lowest average low temperature) is December (28.9°F).
Average pressure in September
Williams, OR
- Average pressure in September: 29.99"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is August (29.98"Hg).
Average wind speed in September
Williams, OR
- Average wind speed in September: 3.4mph
The windiest month (with the highest average wind speed) is March (4.3mph).
The calmest month (with the lowest average wind speed) is August (3.3mph).
Average humidity in September
Williams, OR
- Average humidity in September: 64%
The months with the highest relative humidity are January and December (84%).
The month with the lowest relative humidity is August (60%).
Average rainfall in September
Williams, OR
- Average rainfall in September: 0.43"
The wettest month (with the highest rainfall) is January (2.01").
The driest month (with the least rainfall) is July (0.28").
Average rainfall days in September
Williams, OR
- Average rainfall days in September: 4.4 days
The month with the highest number of rainy days is March (12.1 days).
The month with the least rainy days is August (3.5 days).
Average snowfall in September
Williams, OR
- Average snowfall in September: 0"
The month with the highest snowfall is December (6.3").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Williams, OR
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (7.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Williams, OR
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 10h and 30min
The months with the most sunshine are July and August (Average sunshine: 11h and 48min).
The months with the least sunshine are January and December (Average sunshine: 5h and 0min).
Average sunshine days in September
Williams, OR
- Average sunshine days in September: 25 days
The months with the most sunshine days are July and August (25.3 days).
The month with the least sunshine days is March (15 days).
Average UV index in September
Williams, 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
Williams, OR
- Average cloud cover in September: 22
The month with the most cloud cover is March (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 13).
Average visibility in September
Williams, 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 and December (4mi).





