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
A modest decline in the average high-temperature is seen during September, decreasing from a warm 81.9°F (27.7°C) in August to a still moderately hot 75.6°F (24.2°C). During the month of September, Swissvale's nighttime temperature lowers to an average of 55.6°F (13.1°C).Humidity
In September, the average relative humidity is 77%.Rainfall
In Swissvale, during September, the rain falls for 14.3 days and regularly aggregates up to 2.6" (66mm) of precipitation. Throughout the year, there are 182.2 rainfall days, and 34.84" (885mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In Swissvale, the average length of the day in September is 12h and 27min.On the first day of September, sunrise is at 6:47 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:15 am and sunset at 7:02 pm EDT.
Sunshine
In September, the average sunshine is 8.4h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: The maximum daily UV index, 4 in September, converts into the following recommendations:
Make use of precautions - Suggestions to resist sunburn are communicated. The solar radiation around mid-day is intense; avoid the Sun and stay safe. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in Swissvale in September?
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
Swissvale, PA
- Average high temperature in September: 75.6°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (32.9°F).
- Average low temperature in September: 55.6°F
The month with the highest average low temperature is July (62.1°F).
The coldest month (with the lowest average low temperature) is January (20.7°F).
Average pressure in September
Swissvale, PA
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in September
Swissvale, PA
- Average wind speed in September: 5.2mph
The windiest month (with the highest average wind speed) is January (8.1mph).
The calmest month (with the lowest average wind speed) is August (4.7mph).
Average humidity in September
Swissvale, PA
- Average humidity in September: 77%
The month with the highest relative humidity is February (85%).
The months with the lowest relative humidity are July and August (75%).
Average rainfall in September
Swissvale, PA
- Average rainfall in September: 2.6"
The wettest month (with the highest rainfall) is May (3.58").
The driest month (with the least rainfall) is November (2.17").
Average rainfall days in September
Swissvale, PA
- Average rainfall days in September: 14.3 days
The month with the highest number of rainy days is May (21 days).
The month with the least rainy days is February (10.4 days).
Average snowfall in September
Swissvale, PA
- Average snowfall in September: 0"
The month with the highest snowfall is January (6.42").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Swissvale, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (17.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Swissvale, 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 18min).
- Average sunshine in September: 8h and 2min
The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 2h and 54min).
Average sunshine days in September
Swissvale, PA
- Average sunshine days in September: 13.2 days
The month with the most sunshine days is November (14.8 days).
The month with the least sunshine days is January (7.4 days).
Average UV index in September
Swissvale, PA
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Swissvale, PA
- Average cloud cover in September: 39
The month with the most cloud cover is January (Cloud cover 70).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility in September
Swissvale, PA
- Average visibility in September: 5mi
The months with the highest visibility are April, June, July, August and November (6mi).
The months with the lowest visibility are January and February (4mi).
Swissvale, Pennsylvania, USA
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