September weather forecast
Green Wood Knolls, MD

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Weather in September

The first month of the autumn, September, is also a moderately hot month in Green Wood Knolls, Maryland, with an average temperature varying between 78.1°F (25.6°C) and 60.8°F (16°C).

Temperature

Green Wood Knolls records a mild change in average high-temperature during September, easing from a warm 84.9°F (29.4°C) in August to a still moderately hot 78.1°F (25.6°C). Green Wood Knolls, in the month of September, anticipates a consistent average low-temperature of 60.8°F (16°C).

Humidity

In Green Wood Knolls, the average relative humidity in September is 74%.

Rainfall

In September, the rain falls for 12.5 days. Throughout September, 2.24" (57mm) of precipitation is accumulated. In Green Wood Knolls, during the entire year, the rain falls for 160.9 days and collects up to 32.99" (838mm) of precipitation.

Snowfall

May through October are months without snowfall.

Daylight

In Green Wood Knolls, the average length of the day in September is 12h and 26min.
On the first day of the month, sunrise is at 6:37 am and sunset at 7:38 pm. On the last day of September, sunrise is at 7:04 am and sunset at 6:52 pm EDT.

Sunshine

In September, the average sunshine is 8.9h.

UV index

In Green Wood Knolls, Maryland, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV rays for the average person.
Note: The daily high UV index of 5 in September translates into this advice:
Exercise prevention - Precautions against solar damage are endorsed. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Experience reduced UV exposure by about half when donning a wide-brim hat.

Frequently asked questions

What is the temperature in September?

An average high-temperature, in September, in Green Wood Knolls, is 78.1°F (25.6°C) and the average low-temperature is 60.8°F (16°C). The average heat index (a.k.a. 'felt air temperature', 'feels like'), which represents the influence of relative humidity on air temperature, in August is estimated at 93.2°F (34°C).

What is the average humidity in September?

In Green Wood Knolls, the average relative humidity in September is 74%.

How much does it rain in September?

In Green Wood Knolls, in September, during 12.5 rainfall days, 2.24" (57mm) of precipitation is typically accumulated.

When it does not snow?

May through October are months without snowfall.

How many hours of daylight does Green Wood Knolls have in September?

In Green Wood Knolls, the average day length in September is 12h and 26min.

When is the sunrise / sunset in September?

On the first day of September, sunrise is at 6:37 am and sunset at 7:38 pm. On the last day of the month, sunrise is at 7:04 am and sunset at 6:52 pm EDT.

How long on average sun shines in September?

The average sunshine duration in September is 8.9h.

What is the UV index intensity in September?

The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a medium health risk from 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
Green Wood Knolls, MD

Average temperature in September - Green Wood Knolls, MD
  • Average high temperature in September: 78.1°F

The warmest month (with the highest average high temperature) is July (87.3°F).
The month with the lowest average high temperature is January (39°F).

  • Average low temperature in September: 60.8°F

The month with the highest average low temperature is July (68.7°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).

Average pressure in September
Green Wood Knolls, MD

Average pressure in September - Green Wood Knolls, 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 (29.95"Hg).

Average wind speed in September
Green Wood Knolls, MD

Average wind speed in September - Green Wood Knolls, MD
  • Average wind speed in September: 5.7mph

The windiest month (with the highest average wind speed) is March (8.1mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).

Average humidity in September
Green Wood Knolls, MD

Average humidity in September - Green Wood Knolls, MD
  • Average humidity in September: 74%

The months with the highest relative humidity are May, October and December (76%).
The month with the lowest relative humidity is July (70%).

Average rainfall in September
Green Wood Knolls, MD

Average rainfall in September - Green Wood Knolls, MD
  • Average rainfall in September: 2.24"

The wettest month (with the highest rainfall) is August (4.13").
The driest month (with the least rainfall) is January (2.17").

Average rainfall days in September
Green Wood Knolls, MD

Average rainfall days in September - Green Wood Knolls, MD
  • Average rainfall days in September: 12.5 days

The month with the highest number of rainy days is May (17.8 days).
The month with the least rainy days is November (8.8 days).

Average snowfall in September
Green Wood Knolls, MD

Average snowfall in September - Green Wood Knolls, MD
  • Average snowfall in September: 0"

The months with the highest snowfall are January and March (3.03").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Green Wood Knolls, MD

Average snowfall days in September - Green Wood Knolls, MD
  • Average snowfall days in September: 0 days

The months with the highest number of snowfall days are January and February (5.1 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
Green Wood Knolls, MD

Average daylight in September / Average sunshine in September - Green Wood Knolls, 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: 8h and 5min

The month with the most sunshine is July (Average sunshine: 10h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 0min).

Average sunshine days in September
Green Wood Knolls, MD

Average sunshine days in September - Green Wood Knolls, MD
  • Average sunshine days in September: 15.6 days

The month with the most sunshine days is November (19.4 days).
The months with the least sunshine days are May and July (11 days).

Average UV index in September
Green Wood Knolls, MD

Average UV index in September - Green Wood Knolls, 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).

Average cloud cover in September
Green Wood Knolls, MD

Average cloud cover in September - Green Wood Knolls, MD
  • Average cloud cover in September: 37

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
Green Wood Knolls, MD

Average visibility in September - Green Wood Knolls, MD
  • Average visibility in September: 6mi

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

Green Wood Knolls, Maryland, USA

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