September weather forecastLebanon, OR
September
Weather in September
Fall starts to make its presence known in September in Lebanon, as the weather starts cooling down. From 81.1°F (27.3°C) in August, a downturn in average high temperatures is noticeable, dropping to 73.4°F (23°C). Besides the temperature, the sunshine duration also dwindles, giving way to longer nights. Though the rainfall sees an increase, it continues to remain on the lower side compared to other months. In essence, September brings a subtle shift in climate as it marks the transition from summer to fall.Temperature
September's arrival aligns with a minor decrease in average high-temperatures, from August's warm 81.1°F (27.3°C) to a still moderately hot 73.4°F (23°C). September nights see a notable contrast from daytime highs, with the nighttime temperature averaging at a frosty 48.9°F (9.4°C).Humidity
In Lebanon, the average relative humidity in September is 71%.Rainfall
In Lebanon, during September, the rain falls for 8.8 days and regularly aggregates up to 1.5" (38mm) of precipitation. In Lebanon, during the entire year, the rain falls for 163.3 days and collects up to 29.92" (760mm) of precipitation.Snowfall
In Lebanon, snow does not fall in April through October.Daylight
In Lebanon, the average length of the day in September is 12h and 30min.On the first day of the month, sunrise is at 6:35 am and sunset at 7:47 pm. On the last day of September, sunrise is at 7:09 am and sunset at 6:53 pm PDT.
Sunshine
The average sunshine in September in Lebanon is 9.4h.UV index
In Lebanon, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for the ordinary person.Note: The daily maximum UV index of 4 in September interprets into the following advice:
Heed the precautions - It is counselled to guard against solar damage. The solar radiation around mid-day is intense; avoid the Sun and stay safe. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Lebanon, OR
- Average high temperature in September: 73.4°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 (45.3°F).
- Average low temperature in September: 48.9°F
The month with the highest average low temperature is August (51.8°F).
The coldest month (with the lowest average low temperature) is December (34.2°F).
Average pressure in September
Lebanon, OR
- Average pressure in September: 30.01"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The months with the lowest atmospheric pressure are August and September (30.01"Hg).
Average wind speed in September
Lebanon, OR
- Average wind speed in September: 4mph
The windiest months (with the highest average wind speed) are January and March (5.1mph).
The calmest month (with the lowest average wind speed) is August (3.9mph).
Average humidity in September
Lebanon, OR
- Average humidity in September: 71%
The months with the highest relative humidity are January, February, March and December (86%).
The month with the lowest relative humidity is August (66%).
Average rainfall in September
Lebanon, OR
- Average rainfall in September: 1.5"
The wettest month (with the highest rainfall) is December (4.41").
The driest month (with the least rainfall) is July (0.24").
Average rainfall days in September
Lebanon, OR
- Average rainfall days in September: 8.8 days
The month with the highest number of rainy days is March (20.1 days).
The months with the least rainy days are July and August (3.8 days).
Average snowfall in September
Lebanon, OR
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.13").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Lebanon, OR
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (2.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Lebanon, 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: 9h and 24min
The month with the most sunshine is August (Average sunshine: 11h and 12min).
The month with the least sunshine is February (Average sunshine: 4h and 12min).
Average sunshine days in September
Lebanon, OR
- Average sunshine days in September: 19.3 days
The month with the most sunshine days is July (25.6 days).
The month with the least sunshine days is March (9.1 days).
Average UV index in September
Lebanon, 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
Lebanon, OR
- Average cloud cover in September: 30
The month with the most cloud cover is February (Cloud cover 59).
The month with the least cloud cover is August (Cloud cover 20).
Average visibility in September
Lebanon, OR
- Average visibility in September: 6mi
The months with the highest visibility are July, August and September (6mi).
The month with the lowest visibility is February (4mi).
