September weather forecast
Bristol, PA

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Weather in September

The first month of the autumn, September, is still a warm month in Bristol, Pennsylvania, with an average temperature fluctuating between 76.5°F (24.7°C) and 59.9°F (15.5°C).

Temperature

September is characterized by a slight reduction in average high-temperature, easing from a moderately hot 83.1°F (28.4°C) in August to a still warm 76.5°F (24.7°C). Bristol experiences a steady low-temperature of 59.9°F (15.5°C) throughout September.

Humidity

The average relative humidity in September is 76%.

Rainfall

In Bristol, in September, during 12.7 rainfall days, 1.93" (49mm) of precipitation is typically accumulated. Throughout the year, there are 154.4 rainfall days, and 31.38" (797mm) of precipitation is accumulated.

Snowfall

June through October are months without snowfall.

Daylight

The average length of the day in September is 12h and 26min.
On the first day of the month, sunrise is at 6:27 am and sunset at 7:30 pm. On the last day of September, in Bristol, sunrise is at 6:55 am and sunset at 6:42 pm EDT.

Sunshine

In Bristol, the average sunshine in September is 8.8h.

UV index

In Bristol, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: The maximum daily UV index of 4 in September converts into the following recommendations:
Make use of precautions - It is urged to ward off sun damage. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.
Updated: Jun 28, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

The average high-temperature and low-temperature during September are 76.5°F (24.7°C) and 59.9°F (15.5°C) respectively. In August, the average heat index (a.k.a. 'real feel', 'apparent temperature'), which factors the actual air temperature with the relative humidity, is computed to be 89.6°F (32°C).

What is the average humidity in September?

The average relative humidity in September is 76%.

How much does it rain in September?

In Bristol, during September, the rain falls for 12.7 days and regularly aggregates up to 1.93" (49mm) of precipitation.

When it does not snow?

In Bristol, snow does not fall in June through October.

How many hours of daylight does Bristol have in September?

The average day length in September is 12h and 26min.

When is the sunrise / sunset in September?

On the first day of September, sunrise is at 6:27 am and sunset at 7:30 pm. On the last day of the month, sunrise is at 6:55 am and sunset at 6:42 pm EDT.

How long on average sun shines in September?

In Bristol, the average sunshine duration in September is 8.8h.

What is the UV index reading in September?

In Bristol, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health risk 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
Bristol, PA

Average temperature in September - Bristol, PA
  • Average high temperature in September: 76.5°F

The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is January (37°F).

  • Average low temperature in September: 59.9°F

The month with the highest average low temperature is July (68°F).
The coldest month (with the lowest average low temperature) is January (25.2°F).

Average pressure in September
Bristol, PA

Average pressure in September - Bristol, PA
  • Average pressure in September: 30.05"Hg

The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).

Average wind speed in September
Bristol, PA

Average wind speed in September - Bristol, PA
  • Average wind speed in September: 6mph

The windiest month (with the highest average wind speed) is March (8.6mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).

Average humidity in September
Bristol, PA

Average humidity in September - Bristol, PA
  • Average humidity in September: 76%

The months with the highest relative humidity are February and October (78%).
The month with the lowest relative humidity is April (72%).

Average rainfall in September
Bristol, PA

Average rainfall in September - Bristol, PA
  • Average rainfall in September: 1.93"

The wettest month (with the highest rainfall) is July (3.66").
The driest month (with the least rainfall) is January (1.89").

Average rainfall days in September
Bristol, PA

Average rainfall days in September - Bristol, PA
  • Average rainfall days in September: 12.7 days

The month with the highest number of rainy days is July (18.8 days).
The month with the least rainy days is January (8 days).

Average snowfall in September
Bristol, PA

Average snowfall in September - Bristol, PA
  • Average snowfall in September: 0"

The month with the highest snowfall is March (2.99").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in September
Bristol, PA

Average snowfall days in September - Bristol, PA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (4.8 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
Bristol, PA

Average daylight in September / Average sunshine in September - Bristol, 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 5min

The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 48min).

Average sunshine days in September
Bristol, PA

Average sunshine days in September - Bristol, PA
  • Average sunshine days in September: 14.9 days

The month with the most sunshine days is November (20.6 days).
The month with the least sunshine days is July (9.9 days).

Average UV index in September
Bristol, PA

Average UV index in September - Bristol, 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, November and December (UV index 2).

Average cloud cover in September
Bristol, PA

Average cloud cover in September - Bristol, PA
  • Average cloud cover in September: 37

The months with the most cloud cover are February and March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 32).

Average visibility in September
Bristol, PA

Average visibility in September - Bristol, PA
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is May (5mi).

Bristol, Pennsylvania, USA

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