September weather forecastPenn, PA
September
Weather in September
September, the first month of the autumn in Penn, is still a warm month, with an average temperature fluctuating between 54.5°F (12.5°C) and 74.5°F (23.6°C).Temperature
As August makes way for September, Penn's average high-temperature eases from 81.1°F (27.3°C) to a still warm 74.5°F (23.6°C). In the month of September, the nighttime temperature dips to a steady average of 54.5°F (12.5°C).Humidity
In September, the average relative humidity is 78%.Rainfall
In Penn, in September, during 15.2 rainfall days, 2.48" (63mm) of precipitation is typically accumulated. In Penn, during the entire year, the rain falls for 183.8 days and collects up to 35.16" (893mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
In Penn, the average length of the day in September is 12h and 27min.On the first day of September, sunrise is at 6:46 am and sunset at 7:49 pm. On the last day of the month, sunrise is at 7:14 am and sunset at 7:01 pm EDT.
Sunshine
The average sunshine in September in Penn is 8.7h.UV index
In September, the average daily maximum UV index in Penn is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the average person.Note: The maximum UV index of 4 during September translates into these guidelines:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Fend off the sun's harsh rays with appropriate clothing, a wide-brim hat, and UV-protective sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Penn, PA
- Average high temperature in September: 74.5°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (32.9°F).
- Average low temperature in September: 54.5°F
The month with the highest average low temperature is July (61.2°F).
The coldest month (with the lowest average low temperature) is January (20.5°F).
Average pressure in September
Penn, PA
- Average pressure in September: 30.06"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
Penn, PA
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is January (8.3mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in September
Penn, PA
- Average humidity in September: 78%
The months with the highest relative humidity are January and February (85%).
The months with the lowest relative humidity are April, July and August (77%).
Average rainfall in September
Penn, PA
- Average rainfall in September: 2.48"
The wettest month (with the highest rainfall) is May (3.78").
The driest month (with the least rainfall) is November (2.09").
Average rainfall days in September
Penn, PA
- Average rainfall days in September: 15.2 days
The month with the highest number of rainy days is May (20.1 days).
The month with the least rainy days is January (9.5 days).
Average snowfall in September
Penn, PA
- Average snowfall in September: 0"
The month with the highest snowfall is January (7.05").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Penn, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (18.2 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Penn, 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 42min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 2h and 54min).
Average sunshine days in September
Penn, PA
- Average sunshine days in September: 12.9 days
The month with the most sunshine days is November (14 days).
The month with the least sunshine days is February (6.7 days).
Average UV index in September
Penn, PA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Penn, PA
- Average cloud cover in September: 38
The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in September
Penn, PA
- Average visibility in September: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January and February (4mi).
