September weather forecastBryn Athyn, PA
September
Weather in September
September, the first month of the autumn in Bryn Athyn, is still a warm month, with an average temperature fluctuating between 77°F (25°C) and 60.3°F (15.7°C).Temperature
The transition into September subtly indicates a reduction in the average high-temperature, down to a still moderately hot 77°F (25°C) from August's 84.2°F (29°C). An average nighttime temperature of 60.3°F (15.7°C) is witnessed throughout September.Humidity
In September, the average relative humidity is 74%.Rainfall
In Bryn Athyn, in September, during 12.8 rainfall days, 2.01" (51mm) of precipitation is typically accumulated. In Bryn Athyn, during the entire year, the rain falls for 153.8 days and collects up to 30.94" (786mm) of precipitation.Snowfall
June through October are months without snowfall.Daylight
In Bryn Athyn, the average length of the day in September is 12h and 26min.On the first day of September, sunrise is at 6:28 am and sunset at 7:31 pm. On the last day of the month, sunrise is at 6:56 am and sunset at 6:43 pm EDT.
Sunshine
The average sunshine in September is 8.6h.UV index
In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the average person.Note: An average maximum UV index of 5 in September leads to these recommendations:
Exercise caution. Those with pale skin may experience burns in less than half an hour. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. On days when the sun blazes, arm yourself with sunglasses that block UVA and UVB radiation.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Bryn Athyn, PA
- Average high temperature in September: 77°F
The warmest month (with the highest average high temperature) is July (86.4°F).
The month with the lowest average high temperature is January (37.4°F).
- Average low temperature in September: 60.3°F
The month with the highest average low temperature is July (68.9°F).
The coldest month (with the lowest average low temperature) is January (25.2°F).
Average pressure in September
Bryn Athyn, PA
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Bryn Athyn, PA
- Average wind speed in September: 6mph
The windiest months (with the highest average wind speed) are March and April (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.6mph).
Average humidity in September
Bryn Athyn, PA
- Average humidity in September: 74%
The months with the highest relative humidity are February and October (77%).
The months with the lowest relative humidity are April, July and August (71%).
Average rainfall in September
Bryn Athyn, PA
- Average rainfall in September: 2.01"
The wettest month (with the highest rainfall) is July (3.39").
The driest month (with the least rainfall) is January (1.89").
Average rainfall days in September
Bryn Athyn, PA
- Average rainfall days in September: 12.8 days
The month with the highest number of rainy days is July (18.5 days).
The month with the least rainy days is November (7.5 days).
Average snowfall in September
Bryn Athyn, PA
- Average snowfall in September: 0"
The month with the highest snowfall is March (2.76").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Bryn Athyn, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (5.2 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Bryn Athyn, 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 36min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).
Average sunshine days in September
Bryn Athyn, PA
- Average sunshine days in September: 15.2 days
The month with the most sunshine days is November (21.2 days).
The month with the least sunshine days is July (10.4 days).
Average UV index in September
Bryn Athyn, PA
- Average UV index in September: 5
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Bryn Athyn, PA
- Average cloud cover in September: 39
The month with the most cloud cover is February (Cloud cover 48).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in September
Bryn Athyn, PA
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).





