September weather forecastArnold, PA

September

Weather in September

September, the first month of the autumn in Arnold, is also a moderately hot month, with an average temperature ranging between max 74.8°F (23.8°C) and min 54.7°F (12.6°C).

Temperature

Transitioning from August to September involves a subtle drop in average high-temperatures, descending from 81.3°F (27.4°C) to a still moderately hot 74.8°F (23.8°C). In Arnold, the September nights cool down to an average low of 54.7°F (12.6°C).

Humidity

The average relative humidity in September is 78%.

Rainfall

In Arnold, during September, the rain falls for 14.1 days and regularly aggregates up to 2.56" (65mm) of precipitation. Throughout the year, there are 185.5 rainfall days, and 35.59" (904mm) of precipitation is accumulated.

Snowfall

In Arnold, 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 the month, sunrise is at 6:46 am and sunset at 7:50 pm. On the last day of September, sunrise is at 7:15 am and sunset at 7:02 pm EDT.

Sunshine

In September, the average sunshine is 8.5h.

UV index

The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the ordinary person.
Note: In September, an average UV index of 4 transforms into the following instructions:
Exercise prevention - Precautions against solar damage are endorsed. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat.

Updated: Jun 4, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

An average high-temperature, in September, in Arnold, is 74.8°F (23.8°C) and the average low-temperature is 54.7°F (12.6°C). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which combines air temperature and relative humidity, in August is estimated at 86°F (30°C).

In September, the average relative humidity is 78%.

In Arnold, Pennsylvania, in September, during 14.1 rainfall days, 2.56" (65mm) of precipitation is typically accumulated.

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

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

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

In September, on the first day of the month, sunrise is at 6:46 am and sunset at 7:50 pm. On the last day of the month, sunrise is at 7:15 am and sunset at 7:02 pm EDT.

The average sunshine duration in September is 8.5h.

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a medium hazard to health from exposure to the Sun's UV radiation.

Today

Tomorrow

Long-term

Year J F M A M J J A September O N D

Aug

September

Oct

Average high temperature

81.3°F

74.8°F

61.3°F

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

5.2mph

5.5mph

7mph

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average snowfall

Average snowfall days

Average daylight

Average sunshine

Average sunshine days

13.7

12.8

Average UV index

Average cloud cover

Average visibility

Average temperature in September
Arnold, PA

Average high temperature in September: 74.8°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 (32.7°F).

Average low temperature in September: 54.7°F

The month with the highest average low temperature is July (61.3°F).
The coldest month (with the lowest average low temperature) is January (20.3°F).

Average pressure in September
Arnold, 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
Arnold, 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
Arnold, PA

Average humidity in September: 78%

The month with the highest relative humidity is February (85%).
The months with the lowest relative humidity are April, July and August (76%).

Average rainfall in September
Arnold, PA

Average rainfall in September: 2.56"

The wettest months (with the highest rainfall) are April and May (3.66").
The driest month (with the least rainfall) is November (2.2").

Average rainfall days in September
Arnold, PA

Average rainfall days in September: 14.1 days

The month with the highest number of rainy days is May (20.2 days).
The month with the least rainy days is January (11.1 days).

Average snowfall in September
Arnold, PA

Average snowfall in September: 0"

The month with the highest snowfall is January (6.73").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Arnold, PA

Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (18 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in September: 12h and 24min

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 30min

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).