September weather forecast
Saint Marys, PA

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Weather in September

The first month of the autumn, September, is still a pleasant month in Saint Marys, Pennsylvania, with temperature in the range of an average low of 50.5°F (10.3°C) and an average high of 70.3°F (21.3°C).

Temperature

The arrival of September is marked by a minor reduction in average high-temperature, sliding from a warm 77.5°F (25.3°C) in August to a pleasant 70.3°F (21.3°C). During the month of September, the temperature falls to an average of 50.5°F (10.3°C).

Humidity

In Saint Marys, the average relative humidity in September is 81%.

Rainfall

In Saint Marys, in September, it is raining for 9.9 days, with typically 1.02" (26mm) of accumulated precipitation. In Saint Marys, during the entire year, the rain falls for 118.9 days and collects up to 13.31" (338mm) of precipitation.

Snowfall

June through September are months without snowfall in Saint Marys.

Daylight

The average length of the day in September is 12h and 28min.
On the first day of September, sunrise is at 6:41 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 6:57 pm EDT.

Sunshine

In September, the average sunshine is 8h.

UV index

In Saint Marys, the average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the average person.
Note: A maximum high UV index of 3 in September translates into the following recommendations:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. Considering the harmful UV rays from the Sun during midday, it's essential to reduce exposure. Clothes that are both tight-knit and comfortably loose are prime choices for sun protection.
Updated: Jun 26, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are September temperatures?

September temperatures in Saint Marys, Pennsylvania, vary between a high-temperature of 70.3°F (21.3°C) and a low-temperature of 50.5°F (10.3°C).

What is the average humidity in September?

In September, the average relative humidity is 81%.

How many days does it rain in September?

In September, the rain falls for 9.9 days. Throughout September, 1.02" (26mm) of precipitation is accumulated.

When it does not snow?

June through September are months without snowfall.

Does it snow in September?

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

What is the average length of the day in September?

In September, the average day length is 12h and 28min.

What time are sunrise and sunset in September?

On the first day of September, sunrise is at 6:41 am and sunset at 7:46 pm. On the last day of the month, sunrise is at 7:10 am and sunset at 6:57 pm EDT.

How long on average sun shines in September?

The average sunshine duration in September is 8h.

What is the UV index intensity in September?

In Saint Marys, the average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes 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
Saint Marys, PA

Average temperature in September - Saint Marys, PA
  • Average high temperature in September: 70.3°F

The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (28.8°F).

  • Average low temperature in September: 50.5°F

The month with the highest average low temperature is July (57.2°F).
The coldest month (with the lowest average low temperature) is January (16.3°F).

Average pressure in September
Saint Marys, PA

Average pressure in September - Saint Marys, PA
  • Average pressure in September: 30.06"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
Saint Marys, PA

Average wind speed in September - Saint Marys, PA
  • Average wind speed in September: 6mph

The windiest month (with the highest average wind speed) is January (8.9mph).
The calmest month (with the lowest average wind speed) is August (5.5mph).

Average humidity in September
Saint Marys, PA

Average humidity in September - Saint Marys, PA
  • Average humidity in September: 81%

The month with the highest relative humidity is February (89%).
The months with the lowest relative humidity are June and July (78%).

Average rainfall in September
Saint Marys, PA

Average rainfall in September - Saint Marys, PA
  • Average rainfall in September: 1.02"

The wettest month (with the highest rainfall) is April (1.5").
The driest months (with the least rainfall) are January and November (0.83").

Average rainfall days in September
Saint Marys, PA

Average rainfall days in September - Saint Marys, PA
  • Average rainfall days in September: 9.9 days

The month with the highest number of rainy days is May (15.7 days).
The month with the least rainy days is February (5.1 days).

Average snowfall in September
Saint Marys, PA

Average snowfall in September - Saint Marys, PA
  • Average snowfall in September: 0"

The month with the highest snowfall is February (4.21").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Saint Marys, PA

Average snowfall days in September - Saint Marys, PA
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (12.2 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Saint Marys, PA

Average daylight in September / Average sunshine in September - Saint Marys, 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 12min).

  • Average sunshine in September: 8h and 0min

The months with the most sunshine are July and August (Average sunshine: 9h and 30min).
The month with the least sunshine is January (Average sunshine: 2h and 30min).

Average sunshine days in September
Saint Marys, PA

Average sunshine days in September - Saint Marys, PA
  • Average sunshine days in September: 17.5 days

The month with the most sunshine days is November (18.9 days).
The month with the least sunshine days is May (13 days).

Average UV index in September
Saint Marys, PA

Average UV index in September - Saint Marys, PA
  • Average UV index in September: 3

The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January and December (UV index 1).

Average cloud cover in September
Saint Marys, PA

Average cloud cover in September - Saint Marys, PA
  • Average cloud cover in September: 47

The month with the most cloud cover is January (Cloud cover 77).
The month with the least cloud cover is July (Cloud cover 42).

Average visibility in September
Saint Marys, PA

Average visibility in September - Saint Marys, PA
  • Average visibility in September: 4mi

The months with the highest visibility are January, February, March, April, May, June, July, October, November and December (5mi).
The months with the lowest visibility are August and September (4mi).

Saint Marys, Pennsylvania, USA

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