September weather forecast
Swarthmore, PA

Weather in September

The first month of the autumn, September, is also a moderately hot month in Swarthmore, Pennsylvania, with an average temperature fluctuating between 76.6°F (24.8°C) and 60.8°F (16°C).

Temperature

In September, the average high-temperature marginally drops from a moderately hot 83.5°F (28.6°C) in August to a still warm 76.6°F (24.8°C). The average low-temperature, in Swarthmore, Pennsylvania, is 60.8°F (16°C).

Humidity

In September, the average relative humidity in Swarthmore is 76%.

Rainfall

In Swarthmore, during 12.6 rainfall days, 1.73" (44mm) of precipitation is typically accumulated. Throughout the year, in Swarthmore, there are 148.4 rainfall days, and 25.94" (659mm) of precipitation is accumulated.

Snowfall

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

Daylight

The average length of the day in September is 12h and 26min.
On the first day of September, sunrise is at 6:29 am and sunset at 7:33 pm. On the last day of the month, sunrise is at 6:56 am and sunset at 6:46 pm EDT.

Sunshine

In September, the average sunshine in Swarthmore is 8.9h.

UV index

In Swarthmore, Pennsylvania, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the average person.
Note: The daily maximum UV index of 5 in September interpret into the following advice:
Take precautions - Protection against sun damage is advised. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
[Resources]

FAQ

What is the temperature in September in Swarthmore?

The average high-temperature, in September, in Swarthmore, is 76.6°F (24.8°C), while the average low-temperature is 60.8°F (16°C). The average heat index (a.k.a. 'felt air temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, in August is computed to be 89.6°F (32°C).

What is the average humidity in September in Swarthmore?

The average relative humidity in September in Swarthmore is 76%.

How much does it rain in Swarthmore in September?

In Swarthmore, during September, the rain falls for 12.6 days and regularly aggregates up to 1.73" (44mm) of precipitation.

When it does not snow in Swarthmore?

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

How many hours of daylight does Swarthmore have in September?

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

What time are sunrise and sunset in September in Swarthmore?

On the first day of September in Swarthmore, Pennsylvania, sunrise is at 6:29 am and sunset at 7:33 pm. On the last day of the month, sunrise is at 6:56 am and sunset at 6:46 pm EDT.

How long on average sun shines in September in Swarthmore?

In Swarthmore, the average sunshine duration in September is 8.9h.

How high is the UV index in September in Swarthmore?

The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a medium health risk from exposure to the Sun's UV radiation.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Swarthmore, PA

Average temperature in September - Swarthmore, PA
  • Average high temperature in September: 76.6°F

The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (37.4°F).

  • Average low temperature in September: 60.8°F

The month with the highest average low temperature is July (68.7°F).
The coldest month (with the lowest average low temperature) is January (25.7°F).

[Resources]

Average pressure in September
Swarthmore, PA

Average pressure in September - Swarthmore, PA
  • Average pressure in September: 30.05"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).

[Resources]

Average wind speed in September
Swarthmore, PA

Average wind speed in September - Swarthmore, PA
  • Average wind speed in September: 5.9mph

The windiest month (with the highest average wind speed) is March (8.6mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).

[Resources]

Average humidity in September
Swarthmore, PA

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

The months with the highest relative humidity are February, October and December (77%).
The month with the lowest relative humidity is April (71%).

[Resources]

Average rainfall in September
Swarthmore, PA

Average rainfall in September - Swarthmore, PA
  • Average rainfall in September: 1.73"

The wettest month (with the highest rainfall) is August (3.11").
The driest month (with the least rainfall) is January (1.61").

[Resources]

Average rainfall days in September
Swarthmore, PA

Average rainfall days in September - Swarthmore, PA
  • Average rainfall days in September: 12.6 days

The month with the highest number of rainy days is July (17 days).
The month with the least rainy days is January (7.1 days).

[Resources]

Average snowfall in September
Swarthmore, PA

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

The month with the highest snowfall is March (2.32").
The months with the least snowfall are June, July, August, September and October (0").

[Resources]

Average snowfall days in September
Swarthmore, PA

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

The month with the highest number of snowfall days is February (3.8 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

[Resources]

Average daylight in September /
Average sunshine in September
Swarthmore, PA

Average daylight in September / Average sunshine in September - Swarthmore, PA
  • Average daylight in September: 12h and 26min

The month with the longest days is June (Average daylight: 14h and 58min).
The month with the shortest days is December (Average daylight: 9h and 24min).

  • Average sunshine in September: 8h and 54min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).

[Resources]

Average sunshine days in September
Swarthmore, PA

Average sunshine days in September - Swarthmore, PA
  • Average sunshine days in September: 15.5 days

The month with the most sunshine days is January (20.8 days).
The month with the least sunshine days is July (11.3 days).

[Resources]

Average UV index in September
Swarthmore, PA

Average UV index in September - Swarthmore, PA
  • Average UV index in September: 5

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).

[Resources]

Average cloud cover in September
Swarthmore, PA

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

The month with the most cloud cover is February (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 30).

[Resources]

Average visibility in September
Swarthmore, PA

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

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

[Resources]

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location
* you will be automatically redirected to the weather forecast for your location