September weather forecast and climate
Port Penn, DE

September, the first month of the autumn, in Port Penn, is still a warm month, with average temperature fluctuating between 77°F (25°C) and 61.2°F (16.2°C).

Temperature

In Port Penn, the average high-temperature marginally drops, from 83.5°F (28.6°C) in August, to a still moderately hot 77°F (25°C). In Port Penn, the average low-temperature is 61.2°F (16.2°C).

Humidity

May, June, September and October, with an average relative humidity of 77%, are most humid months in Port Penn.

Rainfall

In Port Penn, Delaware, in September, it is raining for 11.9 days, with typically 1.85" (47mm) of accumulated precipitation. In Port Penn, Delaware, during the entire year, the rain falls for 147.7 days and collects up to 27.8" (706mm) of precipitation.

Snowfall

In Port Penn snow does not fall in June through October.

Daylight

In Port Penn, the average length of the day is 12.4h.

Sunshine

In Port Penn, Delaware, the average sunshine is 9.1h.

UV index

The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a medium health hazard from unprotected exposure to the Sun's UV rays for ordinary individuals.
Note: The daily maximum UV index of 5 interpret into the following advice:
Take precautions - Protection against sun damage is advised. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the temperature in September in Port Penn?

In September, in Port Penn, the average high-temperature is 77°F (25°C), and the average low-temperature is 61.2°F (16.2°C).

What are the most humid months in Port Penn?

Months with the highest humidity are May, June, September and October, with an average relative humidity of 77%.

What is the average humidity in September in Port Penn?

In Port Penn, Delaware, the average relative humidity in September is 77%.

How many days does it rain in September in Port Penn?

In September, in Port Penn, Delaware, the rain falls for 11.9 days. Throughout September, 1.85" (47mm) of precipitation is accumulated.

When it does not snow in Port Penn?

June through October are months without snowfall in Port Penn.

How many hours of daylight does Port Penn have in September?

The average length of the day in September in Port Penn is 12.4h.

How long on average sun shines in September in Port Penn?

In September, the average sunshine in Port Penn, Delaware, is 9.1h.

What is the UV index intensity in September in Port Penn?

In September, the average daily maximum UV index in Port Penn is 5. A UV Index value of 3 to 5 symbolizes a medium hazard to health from unsafe exposure to the Sun's UV rays.
Average temperature in September - Port Penn, DE
  • Average high temperature in September: 77°F

The warmest month (with the highest average high temperature) is July (85.1°F).
The month with the lowest average high temperature is January (38.7°F).

  • Average low temperature in September: 61.2°F

The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (27°F).

Average pressure in September - Port Penn, DE
  • Average pressure in September: 30.05"

The month with the highest atmospheric pressure is November (30.12").
The month with the lowest atmospheric pressure is June (29.94").

Average wind speed in September - Port Penn, DE
  • Average wind speed in September: 6.2mph

The windiest months (with the highest average wind speed) are February, March and April (8.9mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).

Average humidity in September - Port Penn, DE
  • Average humidity in September: 77%

Months with the highest relative humidity are May, June, September and October (77%).
The month with the lowest relative humidity is April (72%).

Average rainfall in September - Port Penn, DE
  • Average rainfall in September: 1.85"

The wettest month (with the highest rainfall) is August (3.23").
The driest month (with the least rainfall) is January (1.77").

Average rainfall days in September - Port Penn, DE
  • Average rainfall days in September: 11.9 days

The month with the highest number of rainy days is May (16.7 days).
The month with the least rainy days is November (8 days).

Average snowfall in September - Port Penn, DE
  • Average snowfall in September: 0"

The month with the highest snowfall is March (2.32").
Months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in September - Port Penn, DE
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (4.2 days).
Months with the least snowfall days are June, July, August, September and October (0 days).

Average daylight in September / Average sunshine in September - Port Penn, DE
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.9h).
The month with the shortest days is December (Average daylight: 9.4h).

  • Average sunshine in September: 9.1h

The month with the most sunshine is July (Average sunshine: 10.7h).
The month with the least sunshine is February (Average sunshine: 4.9h).

Average sunshine days in September - Port Penn, DE
  • Average sunshine days in September: 15.8 days

The month with the most sunshine days is November (20.6 days).
Months with the least sunshine days are May and July (11.8 days).

Average UV index in September - Port Penn, DE
  • Average UV index in September: 5

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

Average cloud cover in September - Port Penn, DE
  • Average cloud cover in September: 36

The month with the most cloud cover is March (Cloud cover 47).
The month with the least cloud cover is July (Cloud cover 31).

Average visibility in September - Port Penn, DE
  • Average visibility in September: 6mi

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