September weather forecast
Shannon Forest, MD

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Weather in September

The first month of the autumn, September, is still a warm month in Shannon Forest, Maryland, with an average temperature fluctuating between 77.2°F (25.1°C) and 62.4°F (16.9°C).

Temperature

The shift from August to September coincides with a small decrease in the average high-temperature, down to a still warm 77.2°F (25.1°C) from a moderately hot 83.8°F (28.8°C). In September, Shannon Forest reports a consistent average low-temperature of 62.4°F (16.9°C) during the nights.

Humidity

In September, the average relative humidity is 75%.

Rainfall

In Shannon Forest, in September, during 13.1 rainfall days, 2.2" (56mm) of precipitation is typically accumulated. In Shannon Forest, during the entire year, the rain falls for 157.2 days and collects up to 30.47" (774mm) of precipitation.

Snowfall

April 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 6:35 am and sunset at 7:36 pm. On the last day of September, in Shannon Forest, sunrise is at 7:02 am and sunset at 6:50 pm EDT.

Sunshine

In September, the average sunshine is 9.3h.

UV index

In September, the average daily maximum UV index in Shannon Forest, Maryland, is 5. A UV Index of 3 to 5 symbolizes a moderate health risk from exposure to the Sun's UV rays for the ordinary person.
Note: The UV index of 5 during September leads to these advisories:
Exercise prevention - Precautions against solar damage are endorsed. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Protect your eyes, ears, face, and neck from the Sun by wearing a wide-brimmed hat.
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Frequently asked questions

What is the average September temperature in Shannon Forest?

The average high-temperature, in September, in Shannon Forest, is 77.2°F (25.1°C), while the average low-temperature is 62.4°F (16.9°C). The average heat index (a.k.a. 'feels like', 'apparent temperature'), which combines air temperature and relative humidity, in August is computed to be 91.4°F (33°C).

What is the average humidity in September in Shannon Forest?

In September, the average relative humidity in Shannon Forest, Maryland, is 75%.

How many days does it rain in September in Shannon Forest?

In Shannon Forest, in September, during 13.1 rainfall days, 2.2" (56mm) of precipitation is typically accumulated.

When it does not snow in Shannon Forest?

In Shannon Forest, snow does not fall in April through October.

How many hours of daylight does Shannon Forest have in September?

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

When is the sunrise / sunset in September in Shannon Forest?

In September, on the first day of the month, sunrise is at 6:35 am and sunset at 7:36 pm. On the last day of the month, in Shannon Forest, Maryland, sunrise is at 7:02 am and sunset at 6:50 pm EDT.

How many hours of sunshine does Shannon Forest have in September?

The average sunshine duration in September in Shannon Forest is 9.3h.

What is the UV index reading in September in Shannon Forest?

In Shannon Forest, Maryland, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate vulnerability 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
Shannon Forest, MD

Average temperature in September - Shannon Forest, MD
  • Average high temperature in September: 77.2°F

The warmest month (with the highest average high temperature) is July (85.5°F).
The month with the lowest average high temperature is January (38.8°F).

  • Average low temperature in September: 62.4°F

The month with the highest average low temperature is July (70.3°F).
The coldest month (with the lowest average low temperature) is January (27.7°F).

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Average pressure in September
Shannon Forest, MD

Average pressure in September - Shannon Forest, MD
  • Average pressure in September: 30.05"Hg

The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

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Average wind speed in September
Shannon Forest, MD

Average wind speed in September - Shannon Forest, MD
  • Average wind speed in September: 6.6mph

The windiest months (with the highest average wind speed) are January, February and March (9.1mph).
The calmest months (with the lowest average wind speed) are July and August (5.8mph).

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Average humidity in September
Shannon Forest, MD

Average humidity in September - Shannon Forest, MD
  • Average humidity in September: 75%

The month with the highest relative humidity is May (77%).
The months with the lowest relative humidity are March, April and July (72%).

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Average rainfall in September
Shannon Forest, MD

Average rainfall in September - Shannon Forest, MD
  • Average rainfall in September: 2.2"

The wettest month (with the highest rainfall) is August (4.09").
The driest month (with the least rainfall) is January (1.81").

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Average rainfall days in September
Shannon Forest, MD

Average rainfall days in September - Shannon Forest, MD
  • Average rainfall days in September: 13.1 days

The month with the highest number of rainy days is May (18 days).
The months with the least rainy days are January and November (8.4 days).

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Average snowfall in September
Shannon Forest, MD

Average snowfall in September - Shannon Forest, MD
  • Average snowfall in September: 0"

The month with the highest snowfall is January (2.09").
The months with the least snowfall are April, May, June, July, August, September and October (0").

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Average snowfall days in September
Shannon Forest, MD

Average snowfall days in September - Shannon Forest, MD
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (3.8 days).
The months with the least snowfall days are April, May, June, July, August, September and October (0 days).

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Average daylight in September /
Average sunshine in September
Shannon Forest, MD

Average daylight in September / Average sunshine in September - Shannon Forest, 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 30min).

  • Average sunshine in September: 9h and 2min

The month with the most sunshine is July (Average sunshine: 10h and 54min).
The month with the least sunshine is February (Average sunshine: 5h and 6min).

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Average sunshine days in September
Shannon Forest, MD

Average sunshine days in September - Shannon Forest, MD
  • Average sunshine days in September: 14.9 days

The month with the most sunshine days is November (19.9 days).
The months with the least sunshine days are May and July (10.8 days).

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Average UV index in September
Shannon Forest, MD

Average UV index in September - Shannon Forest, MD
  • Average UV index in September: 5

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, November and December (UV index 2).

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Average cloud cover in September
Shannon Forest, MD

Average cloud cover in September - Shannon Forest, MD
  • Average cloud cover in September: 34

The month with the most cloud cover is March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 29).

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Average visibility in September
Shannon Forest, MD

Average visibility in September - Shannon Forest, MD
  • Average visibility in September: 6mi

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

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Shannon Forest, Maryland, USA

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