September weather forecast
Belfast, PA

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Belfast, Pennsylvania, with temperature in the range of an average low of 54.3°F (12.4°C) and an average high of 73.9°F (23.3°C).

Temperature

September's arrival signals a moderate reduction in the average high-temperature, easing from a moderately hot 80.2°F (26.8°C) in August to a still warm 73.9°F (23.3°C). Belfast's nights in September experience an average temperature drop to a cool 54.3°F (12.4°C).

Humidity

In Belfast, the average relative humidity in September is 79%.

Rainfall

September is the month with the least rainfall. Rain falls for 10.6 days and accumulates 1.02" (26mm) of precipitation.

Snowfall

In Belfast, snow does not fall in June through September.

Daylight

In September, the average length of the day is 12h and 27min.
On the first day of September, sunrise is at 6:28 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:44 pm EDT.

Sunshine

The average sunshine in September in Belfast is 8.7h.

UV index

In Belfast, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the average person.
Note: The maximum daily UV index of 4 in September interprets into the following recommendations:
Act with care - The suggestion to avoid sunburn is emphasized. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Updated: Jul 16, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

The high-temperature, in September, in Belfast, is 73.9°F (23.3°C), while the low-temperature averages to 54.3°F (12.4°C). The average heat index (a.k.a. 'real feel', 'feels like'), which combines relative humidity and air temperature, in July is calculated to be 89.6°F (32°C).

What is the average humidity in September?

In September, the average relative humidity is 79%.

What is the driest month in Belfast?

September is the month with the least rainfall. Rain falls for 10.6 days and accumulates 1.02" (26mm) of precipitation.

How much does it rain in September?

In Belfast, Pennsylvania, in September, during 10.6 rainfall days, 1.02" (26mm) of precipitation is typically accumulated.

When it does not snow?

In Belfast, Pennsylvania, snow does not fall in June through September.

Does it snow in September?

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

How many hours of daylight does Belfast have in September?

In Belfast, the average day length in September is 12h and 27min.

When are sunrise and sunset in September in Belfast?

On the first day of September, sunrise is at 6:28 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:44 pm EDT.

How long on average sun shines in September?

The average sunshine duration in September is 8.7h.

What is the UV index intensity in September?

The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate vulnerability from exposure to the Sun's 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
Belfast, PA

Average temperature in September - Belfast, PA
  • Average high temperature in September: 73.9°F

The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is January (33.4°F).

  • Average low temperature in September: 54.3°F

The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is January (20.7°F).

Average pressure in September
Belfast, PA

Average pressure in September - Belfast, PA
  • Average pressure in September: 30.06"Hg

The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

Average wind speed in September
Belfast, PA

Average wind speed in September - Belfast, 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 (4.9mph).

Average humidity in September
Belfast, PA

Average humidity in September - Belfast, PA
  • Average humidity in September: 79%

The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is April (76%).

Average rainfall in September
Belfast, PA

Average rainfall in September - Belfast, PA
  • Average rainfall in September: 1.02"

The wettest month (with the highest rainfall) is July (2.32").
The driest month (with the least rainfall) is September (1.02").

Average rainfall days in September
Belfast, PA

Average rainfall days in September - Belfast, PA
  • Average rainfall days in September: 10.6 days

The month with the highest number of rainy days is July (15.1 days).
The month with the least rainy days is January (7.3 days).

Average snowfall in September
Belfast, PA

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

The month with the highest snowfall is February (2.52").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Belfast, PA

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

The month with the highest number of snowfall days is February (6.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Belfast, PA
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in September: 8h and 4min

The month with the most sunshine is July (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).

Average sunshine days in September
Belfast, PA

Average sunshine days in September - Belfast, PA
  • Average sunshine days in September: 17 days

The month with the most sunshine days is January (19.3 days).
The month with the least sunshine days is July (13 days).

Average UV index in September
Belfast, PA

Average UV index in September - Belfast, PA
  • Average UV index in September: 4

The month with the highest UV index is June (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in September
Belfast, PA

Average cloud cover in September - Belfast, PA
  • Average cloud cover in September: 40

The month with the most cloud cover is February (Cloud cover 51).
The month with the least cloud cover is July (Cloud cover 34).

Average visibility in September
Belfast, PA

Average visibility in September - Belfast, PA
  • Average visibility in September: 5mi

The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October, November and December (5mi).

Belfast, Pennsylvania, USA

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