Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
Swarthmore's progression into September involves a minor drop in the average high-temperature, slightly receding from 83.5°F (28.6°C) in August to a still moderately hot 76.6°F (24.8°C). In September, the temperature drops to an average of 60.8°F (16°C) at night.Humidity
In Swarthmore, the average relative humidity in September is 76%.Rainfall
In Swarthmore, Pennsylvania, in September, 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, Pennsylvania, snow does not fall in June through October.Daylight
In Swarthmore, the average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 6:29 am and sunset at 7:32 pm. On the last day of September, sunrise is at 6:57 am and sunset at 6:44 pm EDT.
Sunshine
The average sunshine in September is 8.9h.UV index
In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: The daily maximum UV index of 5 in September interprets into the following advice:
Undertake precautions - It is suggested to shield oneself from sunburn. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
What is the average length of the day in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
How high is the UV index in September?
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).
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).
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).
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%).
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").
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).
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").
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).
Average daylight in September /
Average sunshine in September
Swarthmore, 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 42min).
The month with the least sunshine is February (Average sunshine: 4h and 54min).
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).
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).
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).
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).
Swarthmore, Pennsylvania, USA
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