September weather forecast
New Castle, PA

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Weather in September

New Castle in September is a spectacle of vibrant fall colours, mild temperatures, and captivating beauty. Average temperatures take a dip from the 80.6°F (27°C) seen in August to a more comfortable 73.8°F (23.2°C). The shorter days and longer nights signal the beginning of fall and the end of summer fun. This transitional period also marks the return of rainfall and the transformation of lush green leaves into vivid shades of red and yellow.

Temperature

The arrival of September suggests a slight decrease in the average high-temperature, moving from a warm 80.6°F (27°C) in August to a still moderately hot 73.8°F (23.2°C). New Castle records an average low-temperature of 54°F (12.2°C) throughout the month of September.

Humidity

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

Rainfall

In New Castle, in September, during 15.1 rainfall days, 2.48" (63mm) of precipitation is typically accumulated. Throughout the year, there are 177.6 rainfall days, and 34.92" (887mm) of precipitation is accumulated.

Snowfall

June through September are months without snowfall.

Daylight

In New Castle, the average length of the day in September is 12h and 27min.
On the first day of September, sunrise is at 6:48 am and sunset at 7:53 pm. On the last day of the month, sunrise is at 7:17 am and sunset at 7:04 pm EDT.

Sunshine

The average sunshine in September is 8.2h.

UV index

The average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.
Note: The average daily UV index of 3 in September transforms into the following instructions:
Be vigilant - Preventing sunburn is recommended. The Sun's radiation is especially intense around midday; try to stay in shade during this period. Enhance your sun protection with tightly woven, yet airy clothing.

Frequently asked questions

What is the average September temperature?

The average high-temperature, in September, in New Castle, is 73.8°F (23.2°C), while the average low-temperature is 54°F (12.2°C). In August, the average heat index (a.k.a. 'real feel', 'feels like'), which represents the influence of relative humidity on air temperature, is calculated to be 86°F (30°C).

What is the average humidity in September?

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

How much does it rain in September?

In New Castle, in September, it is raining for 15.1 days, with typically 2.48" (63mm) of accumulated precipitation.

When it does not snow?

June through September are months without snowfall.

Does it snow in September?

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

How many hours of daylight does New Castle have in September?

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

What time are sunrise and sunset in September?

In September, on the first day of the month, sunrise is at 6:48 am and sunset at 7:53 pm. On the last day of the month, sunrise is at 7:17 am and sunset at 7:04 pm EDT.

How long on average sun shines in September?

The average sunshine duration in September is 8.2h.

What is the UV index intensity in September?

In New Castle, the average daily maximum UV index in September is 3. A UV Index value of 3 to 5 symbolizes a medium hazard to health 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
New Castle, PA

Average temperature in September - New Castle, PA
  • Average high temperature in September: 73.8°F

The warmest month (with the highest average high temperature) is July (82°F).
The month with the lowest average high temperature is January (31.5°F).

  • Average low temperature in September: 54°F

The month with the highest average low temperature is July (60.8°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).

Average pressure in September
New Castle, PA

Average pressure in September - New Castle, 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
New Castle, PA

Average wind speed in September - New Castle, PA
  • Average wind speed in September: 5.6mph

The windiest month (with the highest average wind speed) is January (8.3mph).
The calmest month (with the lowest average wind speed) is July (5.1mph).

Average humidity in September
New Castle, PA

Average humidity in September - New Castle, PA
  • Average humidity in September: 79%

The month with the highest relative humidity is February (87%).
The months with the lowest relative humidity are April, May, June, July and August (78%).

Average rainfall in September
New Castle, PA

Average rainfall in September - New Castle, PA
  • Average rainfall in September: 2.48"

The wettest month (with the highest rainfall) is June (3.66").
The driest month (with the least rainfall) is November (2.24").

Average rainfall days in September
New Castle, PA

Average rainfall days in September - New Castle, PA
  • Average rainfall days in September: 15.1 days

The month with the highest number of rainy days is May (19.3 days).
The month with the least rainy days is January (8.8 days).

Average snowfall in September
New Castle, PA

Average snowfall in September - New Castle, PA
  • Average snowfall in September: 0"

The month with the highest snowfall is January (6.93").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
New Castle, PA

Average snowfall days in September - New Castle, PA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (18.6 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
New Castle, PA

Average daylight in September / Average sunshine in September - New Castle, 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 1min

The month with the most sunshine is August (Average sunshine: 10h and 0min).
The month with the least sunshine is January (Average sunshine: 2h and 30min).

Average sunshine days in September
New Castle, PA

Average sunshine days in September - New Castle, PA
  • Average sunshine days in September: 13.1 days

The month with the most sunshine days is November (13.5 days).
The month with the least sunshine days is February (7 days).

Average UV index in September
New Castle, PA

Average UV index in September - New Castle, PA
  • Average UV index in September: 3

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

Average cloud cover in September
New Castle, PA

Average cloud cover in September - New Castle, PA
  • Average cloud cover in September: 41

The month with the most cloud cover is January (Cloud cover 73).
The month with the least cloud cover is August (Cloud cover 36).

Average visibility in September
New Castle, PA

Average visibility in September - New Castle, PA
  • Average visibility in September: 5mi

The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February and December (4mi).

New Castle, Pennsylvania, USA

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