September weather forecast
Brentwood, PA

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Weather in September

The first month of the autumn, September, is still a warm month in Brentwood, Pennsylvania, with an average temperature fluctuating between 75.7°F (24.3°C) and 55.9°F (13.3°C).

Temperature

With the onset of September, the average high-temperature subtly recedes from August's warm 82.2°F (27.9°C) to a still moderately hot 75.7°F (24.3°C). In Brentwood, an average low-temperature of 55.9°F (13.3°C) is recorded during September nights.

Humidity

The average relative humidity in September is 76%.

Rainfall

In Brentwood, in September, it is raining for 13.5 days, with typically 2.2" (56mm) of accumulated precipitation. In Brentwood, during the entire year, the rain falls for 164 days and collects up to 26.89" (683mm) of precipitation.

Snowfall

May through September are months without snowfall.

Daylight

The average length of the day in September is 12h and 27min.
On the first day of September, sunrise is at 6:48 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 7:03 pm EDT.

Sunshine

In September, the average sunshine is 8.4h.

UV index

In Brentwood, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for the average person.
Note: An average maximum UV index of 4 in September leads to these recommendations:
Exercise care. People with light skin might get burns in fewer than 30 minutes. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Updated: Aug 14, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Brentwood in September?

During September, Brentwood experiences an average high-temperature of 75.7°F (24.3°C) and a low-temperature of 55.9°F (13.3°C). The average heat index (a.k.a. 'felt air temperature', 'real feel'), which combines relative humidity and air temperature, in August is appraised at 87.8°F (31°C).

What is the average humidity in September?

The average relative humidity in September is 76%.

How many days does it rain in September?

In September, the rain falls for 13.5 days. Throughout September, 2.2" (56mm) of precipitation is accumulated.

When it does not snow?

In Brentwood, snow does not fall in May through September.

Does it snow in September?

In Brentwood, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September?

In September, the average day length is 12h and 27min.

What time are sunrise and sunset in September?

On the first day of September, sunrise is at 6:48 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 7:03 pm EDT.

How many hours of sunshine does Brentwood have in September?

The average sunshine duration in September is 8.4h.

What is the UV index reading in September?

The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health threat from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Brentwood, PA

Average temperature in September - Brentwood, 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
Brentwood, PA

Average pressure in September - Brentwood, 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
Brentwood, PA

Average wind speed in September - Brentwood, 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
Brentwood, PA

Average humidity in September - Brentwood, 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
Brentwood, PA

Average rainfall in September - Brentwood, 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
Brentwood, PA

Average rainfall days in September - Brentwood, 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
Brentwood, PA

Average snowfall in September - Brentwood, 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
Brentwood, PA

Average snowfall days in September - Brentwood, 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
Brentwood, PA

Average daylight in September / Average sunshine in September - Brentwood, 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 18min).

  • 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
Brentwood, PA

Average sunshine days in September - Brentwood, 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
Brentwood, PA

Average UV index in September - Brentwood, 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
Brentwood, PA

Average cloud cover in September - Brentwood, 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
Brentwood, PA

Average visibility in September - Brentwood, 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).

Brentwood, Pennsylvania, USA

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