Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The start of September involves a subtle temperature drop, shifting from a moderately hot 82.2°F (27.9°C) in August to a still warm 75.7°F (24.3°C). During the month of September, Castle Shannon anticipates a mean low-temperature of 55.9°F (13.3°C).Humidity
The average relative humidity in September is 76%.Rainfall
In Castle Shannon, Pennsylvania, in September, during 13.5 rainfall days, 2.2" (56mm) of precipitation is typically accumulated. In Castle Shannon, during the entire year, the rain falls for 164 days and collects up to 26.89" (683mm) of precipitation.Snowfall
In Castle Shannon, snow does not fall in May through September.Daylight
In Castle Shannon, the average length of the day in September 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
In Castle Shannon, the average sunshine in September is 8.4h.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 unprotected exposure to Sun's UV rays for the ordinary person.Note: The UV index of 4 in September translates into these instructions:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Castle Shannon have in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Castle Shannon have in September?
What is the UV index reading in September in Castle Shannon?
Average temperature in September
Castle Shannon, PA
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (33.4°F).
- Average low temperature in September: 55.9°F
The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (20.8°F).
Average pressure in September
Castle Shannon, 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
Castle Shannon, PA
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is January (7.9mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in September
Castle Shannon, PA
- Average humidity in September: 76%
The months with the highest relative humidity are January and February (84%).
The month with the lowest relative humidity is August (73%).
Average rainfall in September
Castle Shannon, PA
- Average rainfall in September: 2.2"
The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is November (1.61").
Average rainfall days in September
Castle Shannon, PA
- Average rainfall days in September: 13.5 days
The month with the highest number of rainy days is May (18.4 days).
The month with the least rainy days is January (8.5 days).
Average snowfall in September
Castle Shannon, PA
- Average snowfall in September: 0"
The month with the highest snowfall is January (3.46").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Castle Shannon, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (16.3 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
Castle Shannon, PA
- Average daylight in September: 12h and 2min
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 2min
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
Castle Shannon, PA
- Average sunshine days in September: 14 days
The month with the most sunshine days is November (16.4 days).
The month with the least sunshine days is February (9.5 days).
Average UV index in September
Castle Shannon, 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
Castle Shannon, PA
- Average cloud cover in September: 39
The month with the most cloud cover is January (Cloud cover 69).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in September
Castle Shannon, 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).
Castle Shannon, Pennsylvania, USA
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