September weather forecast
Williamsport, MD

Share

Weather in September

September, the first month of the autumn in Williamsport, is still a warm month, with an average temperature ranging between max 76.1°F (24.5°C) and min 56.3°F (13.5°C).

Temperature

Williamsport's weather in September involves a mild decrease in the average high-temperature, moving down slightly from August's moderately hot 83.1°F (28.4°C) to a still warm 76.1°F (24.5°C). Williamsport's nighttime temperature in September falls to an average of 56.3°F (13.5°C).

Humidity

In September, the average relative humidity is 78%.

Rainfall

September is the month with the least rainfall. Rain falls for 12.5 days and accumulates 1.61" (41mm) of precipitation.

Snowfall

May through October are months without snowfall.

Daylight

The average length of the day in September is 12h and 26min.
On the first day of the month, sunrise is at 6:40 am and sunset at 7:41 pm. On the last day of September, sunrise is at 7:07 am and sunset at 6:54 pm EDT.

Sunshine

The average sunshine in September is 8.8h.

UV index

In September, the average daily maximum UV index is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for the ordinary person.
Note: The daily maximum UV index of 4 in September interprets into the following advice:
Make use of precautions - It is urged to ward off sun damage. To protect against the Sun's most potent rays, avoid direct exposure around midday. Wearing sunglasses with both UVA and UVB protection effectively reduces sun-induced eye damage.
Updated: Jul 20, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

During September, Williamsport experiences an average high-temperature of 76.1°F (24.5°C) and a low-temperature of 56.3°F (13.5°C). In August, the average heat index (a.k.a. 'apparent temperature', 'real feel'), which takes the relative humidity and factors it into the air temperature reading, is appraised at 89.6°F (32°C).

What is the average humidity in September in Williamsport?

In September, the average relative humidity is 78%.

What is the driest month?

September is the month with the least rainfall. Rain falls for 12.5 days and accumulates 1.61" (41mm) of precipitation.

How many days does it rain in September?

In Williamsport, during September, the rain falls for 12.5 days and regularly aggregates up to 1.61" (41mm) of precipitation.

When it does not snow?

May through October are months without snowfall.

How many hours of daylight does Williamsport have in September?

The average day length in September is 12h and 26min.

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:40 am and sunset at 7:41 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:54 pm EDT.

How many hours of sunshine does Williamsport have in September?

In Williamsport, the average sunshine duration in September is 8.8h.

What is the UV index reading in September?

In Williamsport, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health threat from unprotected exposure to 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
Williamsport, MD

Average temperature in September - Williamsport, MD
  • Average high temperature in September: 76.1°F

The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (36.9°F).

  • Average low temperature in September: 56.3°F

The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (23.4°F).

Average pressure in September
Williamsport, MD

Average pressure in September - Williamsport, MD
  • Average pressure in September: 30.06"Hg

The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).

Average wind speed in September
Williamsport, MD

Average wind speed in September - Williamsport, MD
  • Average wind speed in September: 4.9mph

The windiest month (with the highest average wind speed) is January (7.5mph).
The calmest month (with the lowest average wind speed) is August (4.3mph).

Average humidity in September
Williamsport, MD

Average humidity in September - Williamsport, MD
  • Average humidity in September: 78%

The month with the highest relative humidity is October (79%).
The month with the lowest relative humidity is July (74%).

Average rainfall in September
Williamsport, MD

Average rainfall in September - Williamsport, MD
  • Average rainfall in September: 1.61"

The wettest month (with the highest rainfall) is May (2.91").
The driest month (with the least rainfall) is September (1.61").

Average rainfall days in September
Williamsport, MD

Average rainfall days in September - Williamsport, MD
  • Average rainfall days in September: 12.5 days

The month with the highest number of rainy days is May (17.6 days).
The month with the least rainy days is January (8.2 days).

Average snowfall in September
Williamsport, MD

Average snowfall in September - Williamsport, MD
  • Average snowfall in September: 0"

The month with the highest snowfall is January (3.58").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Williamsport, MD

Average snowfall days in September - Williamsport, MD
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (6.2 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight in September /
Average sunshine in September
Williamsport, MD

Average daylight in September / Average sunshine in September - Williamsport, MD
  • Average daylight in September: 12h and 2min

The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).

  • Average sunshine in September: 8h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 36min).
The months with the least sunshine are January and February (Average sunshine: 4h and 48min).

Average sunshine days in September
Williamsport, MD

Average sunshine days in September - Williamsport, MD
  • Average sunshine days in September: 15.1 days

The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is May (11.7 days).

Average UV index in September
Williamsport, MD

Average UV index in September - Williamsport, MD
  • Average UV index in September: 4

The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average cloud cover in September
Williamsport, MD

Average cloud cover in September - Williamsport, MD
  • Average cloud cover in September: 38

The month with the most cloud cover is January (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 31).

Average visibility in September
Williamsport, MD

Average visibility in September - Williamsport, MD
  • Average visibility in September: 5mi

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

Williamsport, Maryland, USA

Weather forecast for your location

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