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
As September commences, the average high-temperature subtly reduces, transitioning from 81.9°F (27.7°C) in August to a still moderately hot 75.4°F (24.1°C). Throughout September, the average low-temperature records at a moderate 57.2°F (14°C).Humidity
In September, the average relative humidity is 78%.Rainfall
In Frederick, in September, during 11 rainfall days, 0.91" (23mm) of precipitation is typically accumulated. Throughout the year, there are 128.6 rainfall days, and 15.16" (385mm) of precipitation is accumulated.Snowfall
In Frederick, Pennsylvania, snow does not fall in June through October.Daylight
In Frederick, the average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:30 am and sunset at 7:33 pm. On the last day of September, sunrise is at 6:58 am and sunset at 6:45 pm EDT.
Sunshine
In Frederick, the average sunshine in September is 8.7h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for average individuals.Note: An average UV index of 4 in September transforms into this advice:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.
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 many days does it rain in September?
When it does not snow in Frederick?
What is the average length of the day in September?
When is the sunrise / sunset in September?
How many hours of sunshine does Frederick have in September?
What is the UV index intensity in September?
Average temperature in September
Frederick, PA
- Average high temperature in September: 75.4°F
The warmest month (with the highest average high temperature) is July (84.6°F).
The month with the lowest average high temperature is January (35.2°F).
- Average low temperature in September: 57.2°F
The month with the highest average low temperature is July (65.3°F).
The coldest month (with the lowest average low temperature) is January (22.8°F).
Average pressure in September
Frederick, PA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Frederick, PA
- Average wind speed in September: 5.5mph
The windiest month (with the highest average wind speed) is March (8.1mph).
The calmest month (with the lowest average wind speed) is August (5mph).
Average humidity in September
Frederick, PA
- Average humidity in September: 78%
The month with the highest relative humidity is February (81%).
The months with the lowest relative humidity are April and July (75%).
Average rainfall in September
Frederick, PA
- Average rainfall in September: 0.91"
The wettest month (with the highest rainfall) is July (1.97").
The driest month (with the least rainfall) is January (0.87").
Average rainfall days in September
Frederick, PA
- Average rainfall days in September: 11 days
The month with the highest number of rainy days is July (15.7 days).
The month with the least rainy days is January (5.7 days).
Average snowfall in September
Frederick, PA
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.46").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Frederick, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (5.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Frederick, 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 4min
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 36min).
Average sunshine days in September
Frederick, PA
- Average sunshine days in September: 17.1 days
The month with the most sunshine days is November (21.4 days).
The month with the least sunshine days is July (12.8 days).
Average UV index in September
Frederick, PA
- Average UV index in September: 4
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
Frederick, PA
- Average cloud cover in September: 39
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in September
Frederick, 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).
Frederick, Pennsylvania, USA
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