September weather forecastMount Lebanon, PA
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Mount Lebanon, Pennsylvania, with temperature in the range of an average high of 75.7°F (24.3°C) and an average low of 55.8°F (13.2°C).Temperature
With the arrival of September, Mount Lebanon notices a mild change in the average high-temperature, sliding from August's 82.4°F (28°C) to a still moderately hot 75.7°F (24.3°C). The nights of September anticipate an average low-temperature of 55.8°F (13.2°C).Humidity
In Mount Lebanon, the average relative humidity in September is 77%.Rainfall
In Mount Lebanon, in September, it is raining for 10.6 days, with typically 0.79" (20mm) of accumulated precipitation. In Mount Lebanon, during the entire year, the rain falls for 132.6 days and collects up to 11.5" (292mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In September, the average length of the day is 12h and 27min.On the first day of the month, sunrise is at 6:48 am and sunset at 7:51 pm. On the last day of September, sunrise is at 7:16 am and sunset at 7:03 pm EDT.
Sunshine
The average sunshine in September is 8.5h.UV index
In September, the average daily maximum UV index in Mount Lebanon is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for average individuals.Note: The maximum UV index of 4 during September leads to these instructions:
Ensure safety - Sun damage prevention is strongly urged. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Loose clothes with a tight weave are optimal for safeguarding yourself against the Sun's rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mount Lebanon, PA
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (33.4°F).
- Average low temperature in September: 55.8°F
The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (21°F).
Average pressure in September
Mount Lebanon, PA
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in September
Mount Lebanon, PA
- Average wind speed in September: 5.1mph
The windiest month (with the highest average wind speed) is January (7.9mph).
The calmest months (with the lowest average wind speed) are July and August (4.7mph).
Average humidity in September
Mount Lebanon, PA
- Average humidity in September: 77%
The month with the highest relative humidity is February (85%).
The months with the lowest relative humidity are July and August (75%).
Average rainfall in September
Mount Lebanon, PA
- Average rainfall in September: 0.79"
The wettest month (with the highest rainfall) is July (1.34").
The driest month (with the least rainfall) is November (0.67").
Average rainfall days in September
Mount Lebanon, PA
- Average rainfall days in September: 10.6 days
The month with the highest number of rainy days is July (15.6 days).
The month with the least rainy days is February (6.4 days).
Average snowfall in September
Mount Lebanon, PA
- Average snowfall in September: 0"
The month with the highest snowfall is February (0.98").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Mount Lebanon, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (9.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Mount Lebanon, PA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 8h and 30min
The month with the most sunshine is August (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).
Average sunshine days in September
Mount Lebanon, PA
- Average sunshine days in September: 16.4 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is May (12.2 days).
Average UV index in September
Mount Lebanon, PA
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Mount Lebanon, PA
- Average cloud cover in September: 38
The month with the most cloud cover is January (Cloud cover 68).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in September
Mount Lebanon, PA
- Average visibility in September: 5mi
The months with the highest visibility are April, June, July, August and November (6mi).
The months with the lowest visibility are January, February, March, May, September, October and December (5mi).





