September weather forecast
Porters Mill, PA

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Weather in September

The first month of the autumn, September, is still a warm month in Porters Mill, Pennsylvania, with an average temperature fluctuating between 75.2°F (24°C) and 57.2°F (14°C).

Temperature

As August makes way for September, Porters Mill's average high-temperature eases from 81.9°F (27.7°C) to a still warm 75.2°F (24°C). Throughout September, Porters Mill anticipates an average low-temperature of 57.2°F (14°C).

Humidity

The average relative humidity in September in Porters Mill is 78%.

Rainfall

September is the month with the least rainfall in Porters Mill. Rain falls for 12.3 days and accumulates 1.81" (46mm) of precipitation.

Snowfall

May through October are months without snowfall in Porters Mill.

Daylight

In Porters Mill, 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 6:46 pm EDT.

Sunshine

In Porters Mill, the average sunshine in September is 8.8h.

UV index

The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: A typical high UV index of 4 in September suggests the following recommendations:
Take necessary precautions - Suggestions to elude sunburn are provided. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Updated: Feb 13, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the temperature in September in Porters Mill?

The average high-temperature and low-temperature in Porters Mill, Pennsylvania, during September are 75.2°F (24°C) and 57.2°F (14°C) respectively. In August, the average heat index (a.k.a. 'felt air temperature', 'feels like'), which represents the influence of relative humidity on air temperature, is computed to be 87.8°F (31°C).

What is the average humidity in September in Porters Mill?

In September, the average relative humidity in Porters Mill is 78%.

What is the driest month in Porters Mill?

September is the month with the least rainfall in Porters Mill. Rain falls for 12.3 days and accumulates 1.81" (46mm) of precipitation.

How many days does it rain in September in Porters Mill?

In Porters Mill, Pennsylvania, during September, the rain falls for 12.3 days and regularly aggregates up to 1.81" (46mm) of precipitation.

When it does not snow in Porters Mill?

May through October are months without snowfall.

What is the average length of the day in September in Porters Mill?

In September, the average day length in Porters Mill, Pennsylvania, is 12h and 27min.

When is the sunrise / sunset in September in Porters Mill?

In September, on the first day of the month, sunrise is at 6:30 am and sunset at 7:33 pm. On the last day of the month, in Porters Mill, sunrise is at 6:58 am and sunset at 6:46 pm EDT.

How long on average sun shines in September in Porters Mill?

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

What is the UV index intensity in September in Porters Mill?

The average daily maximum UV index in September in Porters Mill is 4. A UV Index reading of 3 to 5 represents a medium health risk from unprotected exposure to UV radiation.
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
Porters Mill, PA

Average temperature in September - Porters Mill, PA
  • Average high temperature in September: 75.2°F

The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (35.4°F).

  • Average low temperature in September: 57.2°F

The month with the highest average low temperature is July (65.5°F).
The coldest month (with the lowest average low temperature) is January (23.2°F).

Average pressure in September
Porters Mill, PA

Average pressure in September - Porters Mill, 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
Porters Mill, PA

Average wind speed in September - Porters Mill, 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
Porters Mill, PA

Average humidity in September - Porters Mill, PA
  • Average humidity in September: 78%

The months with the highest relative humidity are February and October (80%).
The months with the lowest relative humidity are April and July (75%).

Average rainfall in September
Porters Mill, PA

Average rainfall in September - Porters Mill, PA
  • Average rainfall in September: 1.81"

The wettest month (with the highest rainfall) is August (3.15").
The driest month (with the least rainfall) is September (1.81").

Average rainfall days in September
Porters Mill, PA

Average rainfall days in September - Porters Mill, PA
  • Average rainfall days in September: 12.3 days

The months with the highest number of rainy days are May and July (17 days).
The month with the least rainy days is January (7.3 days).

Average snowfall in September
Porters Mill, PA

Average snowfall in September - Porters Mill, PA
  • Average snowfall in September: 0"

The month with the highest snowfall is March (3.7").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Porters Mill, PA

Average snowfall days in September - Porters Mill, PA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (5.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Porters Mill, PA

Average daylight in September / Average sunshine in September - Porters Mill, 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 42min).

Average sunshine days in September
Porters Mill, PA

Average sunshine days in September - Porters Mill, PA
  • Average sunshine days in September: 16.4 days

The month with the most sunshine days is November (21 days).
The month with the least sunshine days is May (12.3 days).

Average UV index in September
Porters Mill, PA

Average UV index in September - Porters Mill, 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
Porters Mill, PA

Average cloud cover in September - Porters Mill, PA
  • Average cloud cover in September: 38

The month with the most cloud cover is February (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 32).

Average visibility in September
Porters Mill, PA

Average visibility in September - Porters Mill, 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).

Porters Mill, Pennsylvania, USA

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