September weather forecast
Pittsburgh, PA

englishespañol中文
Share
A beautiful dusk panorama of Pittsburgh, Pennsylvania, with the river and several bridges
A beautiful dusk panorama of Pittsburgh, Pennsylvania, with the river and several bridges

Weather in September

September in Pittsburgh greets autumn with open arms, showcasing a steady decrease in temperatures, resulting in comfortable, moderate weather. The daylight hours reduce significantly from August down to 12.5 hours along with a slight increase in rainfall. The changing season breathes a new lease of life into the city, dressing it in captivating hues of autumn. It's a prime time for activities that require milder weather and less crowded tourist spots. As the season progresses, the city gears up to witness the mesmerizing fall foliage, a highlight of Pittsburgh's year.

Temperature

With the onset of September, Pittsburgh's average high-temperature slightly adjusts, moderately receding from August's 82.2°F (27.9°C) to a still moderately hot 75.7°F (24.3°C). The low-temperature average for Pittsburgh during September stands at a mild 55.9°F (13.3°C).

Humidity

The average relative humidity in September in Pittsburgh, Pennsylvania, is 76%.

Rainfall

In September, the rain falls for 12.9 days. Throughout September, 2.13" (54mm) of precipitation is accumulated. Throughout the year, there are 163.6 rainfall days, and 26.93" (684mm) of precipitation is accumulated.

Snowfall

May through September are months without snowfall.

Daylight

In Pittsburgh, the average length of the day in September is 12h and 27min.
On the first day of the month, sunrise is at 6:48 am and sunset at 7:51 pm. On the last day of September, sunrise is at 7:16 am and sunset at 7:03 pm EDT.

Sunshine

In Pittsburgh, the average sunshine in September is 8.2h.

UV index

In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV radiation for average individuals.
Note: In September, the UV index of 4 transforms into the following advice:
Guard yourself - An obligation to protect skin and eyes from harm exists. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. Your best bet for sun defense on the face, eyes, and neck is a hat with a wide brim.

Frequently asked questions

What is the average September temperature?

An average high-temperature, in September, in Pittsburgh, is 75.7°F (24.3°C) and the average low-temperature is 55.9°F (13.3°C). In August, the average heat index (a.k.a. 'real feel', 'felt air temperature'), which calculates the temperature value influenced by the moisture in the air, is evaluated at 87.8°F (31°C).

What is the average humidity in September in Pittsburgh?

In September, the average relative humidity is 76%.

How many days does it rain in September?

In Pittsburgh, in September, it is raining for 12.9 days, with typically 2.13" (54mm) of accumulated precipitation.

When it does not snow?

May through September are months without snowfall in Pittsburgh.

Does it snow in September?

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

What is the average length of the day in September?

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

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:48 am and sunset at 7:51 pm. On the last day of the month, sunrise is at 7:16 am and sunset at 7:03 pm EDT.

How long on average sun shines in September?

In September, the average sunshine duration is 8.2h.

How high is the UV index in September?

In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a medium health risk from unsafe 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
Pittsburgh, PA

Average temperature in September - Pittsburgh, PA
  • Average high temperature in September: 75.7°F

The warmest month (with the highest average high temperature) is July (84°F).
The month with the lowest average high temperature is January (33.1°F).

  • Average low temperature in September: 55.9°F

The month with the highest average low temperature is July (63°F).
The coldest month (with the lowest average low temperature) is January (21°F).

Average pressure in September
Pittsburgh, PA

Average pressure in September - Pittsburgh, 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
Pittsburgh, PA

Average wind speed in September - Pittsburgh, PA
  • Average wind speed in September: 5.2mph

The windiest month (with the highest average wind speed) is January (8mph).
The calmest months (with the lowest average wind speed) are July and August (4.8mph).

Average humidity in September
Pittsburgh, PA

Average humidity in September - Pittsburgh, PA
  • Average humidity in September: 76%

The months with the highest relative humidity are January and February (84%).
The months with the lowest relative humidity are July and August (73%).

Average rainfall in September
Pittsburgh, PA

Average rainfall in September - Pittsburgh, PA
  • Average rainfall in September: 2.13"

The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is November (1.54").

Average rainfall days in September
Pittsburgh, PA

Average rainfall days in September - Pittsburgh, PA
  • Average rainfall days in September: 12.9 days

The month with the highest number of rainy days is May (18.9 days).
The month with the least rainy days is January (8.9 days).

Average snowfall in September
Pittsburgh, PA

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

The month with the highest snowfall is January (3.31").
The months with the least snowfall are May, June, July, August and September (0").

Average snowfall days in September
Pittsburgh, PA

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

The month with the highest number of snowfall days is January (14.4 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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

Average daylight in September / Average sunshine in September - Pittsburgh, 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 1min

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 48min).

Average sunshine days in September
Pittsburgh, PA

Average sunshine days in September - Pittsburgh, PA
  • Average sunshine days in September: 13.8 days

The month with the most sunshine days is November (16.5 days).
The month with the least sunshine days is February (9.6 days).

Average UV index in September
Pittsburgh, PA

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

The months with the highest UV index are May, June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).

Average cloud cover in September
Pittsburgh, PA

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

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
Pittsburgh, PA

Average visibility in September - Pittsburgh, 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, February, March, May, September, October and December (5mi).

Pittsburgh, Pennsylvania, USA

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location