September weather forecast
Newtown Square, PA

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Weather in September

September, the first month of the autumn in Newtown Square, is still a warm month, with temperature in the range of an average high of 75.9°F (24.4°C) and an average low of 59.5°F (15.3°C).

Temperature

As August shifts into September, a minor alteration in temperatures is observed, with average highs reducing from 82.9°F (28.3°C) to a still moderately hot 75.9°F (24.4°C). Newtown Square's temperature in September lowers to a consistent average of 59.5°F (15.3°C) during the nights.

Humidity

The average relative humidity in September in Newtown Square is 76%.

Rainfall

In September, in Newtown Square, the rain falls for 11.9 days. Throughout September, 1.34" (34mm) of precipitation is accumulated. Throughout the year, there are 138.1 rainfall days, and 20.79" (528mm) of precipitation is accumulated.

Snowfall

June through September 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 6:30 am and sunset at 7:32 pm. On the last day of September, sunrise is at 6:57 am and sunset at 6:45 pm EDT.

Sunshine

The average sunshine in September is 8.5h.

UV index

In Newtown Square, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for the average person.
Note: In September, the average maximum UV index of 4 translates into the following recommendations:
Undertake protective steps - Preventing sun damage is advised. It's recommended to limit sun exposure when its radiation is at its peak during midday. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.
Updated: Jun 28, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

In Newtown Square, 75.9°F (24.4°C) is the average high-temperature and 59.5°F (15.3°C) is the average low-temperature during September. The average heat index (a.k.a. 'feels like', 'apparent temperature'), which represents the influence of relative humidity on air temperature, in August is calculated to be 89.6°F (32°C).

What is the average humidity in September?

In September, the average relative humidity is 76%.

How much does it rain in September?

In Newtown Square, during September, the rain falls for 11.9 days and regularly aggregates up to 1.34" (34mm) of precipitation.

When it does not snow?

June through September are months without snowfall.

Does it snow in September?

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

How many hours of daylight does Newtown Square have in September?

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

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:30 am and sunset at 7:32 pm. On the last day of the month, in Newtown Square, Pennsylvania, sunrise is at 6:57 am and sunset at 6:45 pm EDT.

How many hours of sunshine does Newtown Square have in September?

In Newtown Square, Pennsylvania, the average sunshine duration in September is 8.5h.

What is the UV index reading in September?

The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate vulnerability 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
Newtown Square, PA

Average temperature in September - Newtown Square, PA
  • Average high temperature in September: 75.9°F

The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is January (36.5°F).

  • Average low temperature in September: 59.5°F

The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).

Average pressure in September
Newtown Square, PA

Average pressure in September - Newtown Square, 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
Newtown Square, PA

Average wind speed in September - Newtown Square, PA
  • Average wind speed in September: 5.7mph

The windiest month (with the highest average wind speed) is March (8.4mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).

Average humidity in September
Newtown Square, PA

Average humidity in September - Newtown Square, PA
  • Average humidity in September: 76%

The months with the highest relative humidity are February and October (79%).
The months with the lowest relative humidity are April, July and August (73%).

Average rainfall in September
Newtown Square, PA

Average rainfall in September - Newtown Square, PA
  • Average rainfall in September: 1.34"

The wettest month (with the highest rainfall) is August (2.72").
The driest months (with the least rainfall) are January, February and November (1.3").

Average rainfall days in September
Newtown Square, PA

Average rainfall days in September - Newtown Square, PA
  • Average rainfall days in September: 11.9 days

The month with the highest number of rainy days is July (16.8 days).
The month with the least rainy days is January (6.3 days).

Average snowfall in September
Newtown Square, PA

Average snowfall in September - Newtown Square, PA
  • Average snowfall in September: 0"

The month with the highest snowfall is March (1.93").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Newtown Square, PA

Average snowfall days in September - Newtown Square, PA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (6.1 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Newtown Square, PA

Average daylight in September / Average sunshine in September - Newtown Square, 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 3min

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 30min).

Average sunshine days in September
Newtown Square, PA

Average sunshine days in September - Newtown Square, PA
  • Average sunshine days in September: 16.4 days

The month with the most sunshine days is November (20.1 days).
The month with the least sunshine days is July (12.7 days).

Average UV index in September
Newtown Square, PA

Average UV index in September - Newtown Square, 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
Newtown Square, PA

Average cloud cover in September - Newtown Square, PA
  • Average cloud cover in September: 41

The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 33).

Average visibility in September
Newtown Square, PA

Average visibility in September - Newtown Square, 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).

Newtown Square, Pennsylvania, USA

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