September weather forecast
Lebanon, OR

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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

Lebanon's September weather shows a modest shift in high-temperatures, falling from August's warm 81.1°F (27.3°C) to a still moderately hot 73.4°F (23°C). Lebanon, amid September nights, sees a noteworthy disparity from daily highs with an average temperature of 48.9°F (9.4°C).

Humidity

In Lebanon, the average relative humidity in September is 71%.

Rainfall

In Lebanon, in September, it is raining for 8.8 days, with typically 1.5" (38mm) of accumulated precipitation. Throughout the year, there are 163.3 rainfall days, and 29.92" (760mm) of precipitation is accumulated.

Snowfall

April through October are months without snowfall.

Daylight

In Lebanon, the average length of the day in September is 12h and 30min.
On the first day of September, sunrise is at 6:35 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:09 am and sunset at 6:53 pm PDT.

Sunshine

The average sunshine in September is 9.4h.

UV index

The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.
Note: The maximum UV index of 4 during September leads to these instructions:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. Avoiding the Sun during its peak radiation time around midday is a healthy practice. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.

Frequently asked questions

What is the usual temperature for Lebanon in September?

An average high-temperature, in September, in Lebanon, is 73.4°F (23°C) and the average low-temperature is 48.9°F (9.4°C). In August, the average heat index (a.k.a. 'feels like', 'real feel'), which factors the actual air temperature with the relative humidity, is calculated to be 84.2°F (29°C).

What is the average humidity in September?

In Lebanon, the average relative humidity in September is 71%.

How many days does it rain in September?

In Lebanon, in September, during 8.8 rainfall days, 1.5" (38mm) of precipitation is typically accumulated.

When it does not snow?

In Lebanon, snow does not fall in April through October.

How many hours of daylight does Lebanon have in September?

In Lebanon, the average day length in September is 12h and 30min.

When is the sunrise / sunset in September?

In September, on the first day of the month, sunrise is at 6:35 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 7:09 am and sunset at 6:53 pm PDT.

How long on average sun shines in September?

In Lebanon, the average sunshine duration in September is 9.4h.

How high is the UV index in September?

In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium hazard to health from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Lebanon, OR

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 - 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 - 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 - 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 - 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 - 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 - 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 - 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 / Average sunshine in September - Lebanon, OR
  • Average daylight in September: 12h and 3min

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 2min

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 - 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 - 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 - 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 - 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).

Lebanon, Oregon, USA

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