September weather forecast
Gwynn Oak, MD

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Weather in September

September, the first month of the autumn in Gwynn Oak, is also a moderately hot month, with an average temperature ranging between max 76.5°F (24.7°C) and min 60.3°F (15.7°C).

Temperature

September's arrival aligns with a minor decrease in average high-temperatures, from August's warm 83.1°F (28.4°C) to a still moderately hot 76.5°F (24.7°C). In September, Gwynn Oak's temperature tends to fall to an average low of 60.3°F (15.7°C) during the night.

Humidity

The average relative humidity in September in Gwynn Oak is 76%.

Rainfall

In Gwynn Oak, in September, it is raining for 13.5 days, with typically 2.2" (56mm) of accumulated precipitation. In Gwynn Oak, during the entire year, the rain falls for 160.6 days and collects up to 31.3" (795mm) of precipitation.

Snowfall

In Gwynn Oak, snow does not fall in May through October.

Daylight

In September, the average length of the day in Gwynn Oak, Maryland, is 12h and 26min.
On the first day of September in Gwynn Oak, Maryland, sunrise is at 6:35 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:50 pm EDT.

Sunshine

The average sunshine in September in Gwynn Oak is 9.1h.

UV index

In Gwynn Oak, Maryland, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from unsafe exposure to UV radiation for the average person.
Note: The maximum UV index, 5 during September, leads to the following recommendations:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The midday Sun can be harmful due to its potent UV radiation; seek shade and reduce exposure. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.
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Frequently asked questions

What is the average September temperature in Gwynn Oak?

During September, Gwynn Oak experiences an average high-temperature of 76.5°F (24.7°C) and a low-temperature of 60.3°F (15.7°C). The average heat index (a.k.a. 'feels like', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, in August is computed to be 89.6°F (32°C).

What is the average humidity in September in Gwynn Oak?

In September, the average relative humidity in Gwynn Oak is 76%.

How many days does it rain in September in Gwynn Oak?

In September, in Gwynn Oak, the rain falls for 13.5 days. Throughout September, 2.2" (56mm) of precipitation is accumulated.

When it does not snow in Gwynn Oak?

May through October are months without snowfall in Gwynn Oak, Maryland.

What is the average length of the day in September in Gwynn Oak?

The average day length in September in Gwynn Oak, Maryland, is 12h and 26min.

When are sunrise and sunset in September in Gwynn Oak?

On the first day of September in Gwynn Oak, Maryland, sunrise is at 6:35 am and sunset at 7:37 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:50 pm EDT.

How long on average sun shines in September in Gwynn Oak?

The average sunshine duration in September in Gwynn Oak, Maryland, is 9.1h.

How high is the UV index in September in Gwynn Oak?

The average daily maximum UV index in September in Gwynn Oak is 5. A UV Index reading of 3 to 5 represents 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
Gwynn Oak, MD

Average temperature in September - Gwynn Oak, MD
  • Average high temperature in September: 76.5°F

The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is January (37.9°F).

  • Average low temperature in September: 60.3°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 (26.1°F).

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Average pressure in September
Gwynn Oak, MD

Average pressure in September - Gwynn Oak, 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
Gwynn Oak, MD

Average wind speed in September - Gwynn Oak, MD
  • Average wind speed in September: 6.2mph

The windiest month (with the highest average wind speed) is March (8.9mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).

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Average humidity in September
Gwynn Oak, MD

Average humidity in September - Gwynn Oak, MD
  • Average humidity in September: 76%

The month with the highest relative humidity is May (78%).
The month with the lowest relative humidity is July (72%).

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Average rainfall in September
Gwynn Oak, MD

Average rainfall in September - Gwynn Oak, MD
  • Average rainfall in September: 2.2"

The wettest month (with the highest rainfall) is August (3.94").
The driest months (with the least rainfall) are January and February (2.01").

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Average rainfall days in September
Gwynn Oak, MD

Average rainfall days in September - Gwynn Oak, MD
  • Average rainfall days in September: 13.5 days

The month with the highest number of rainy days is July (18.3 days).
The month with the least rainy days is February (8.8 days).

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Average snowfall in September
Gwynn Oak, MD

Average snowfall in September - Gwynn Oak, MD
  • Average snowfall in September: 0"

The month with the highest snowfall is March (2.72").
The months with the least snowfall are May, June, July, August, September and October (0").

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Average snowfall days in September
Gwynn Oak, MD

Average snowfall days in September - Gwynn Oak, MD
  • Average snowfall days in September: 0 days

The months with the highest number of snowfall days are January and February (5.3 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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Average daylight in September /
Average sunshine in September
Gwynn Oak, MD

Average daylight in September / Average sunshine in September - Gwynn Oak, 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 1min

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).

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Average sunshine days in September
Gwynn Oak, MD

Average sunshine days in September - Gwynn Oak, MD
  • Average sunshine days in September: 14.2 days

The month with the most sunshine days is November (19.4 days).
The month with the least sunshine days is May (10.7 days).

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Average UV index in September
Gwynn Oak, MD

Average UV index in September - Gwynn Oak, 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, February, November and December (UV index 2).

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Average cloud cover in September
Gwynn Oak, MD

Average cloud cover in September - Gwynn Oak, MD
  • Average cloud cover in September: 35

The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 30).

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Average visibility in September
Gwynn Oak, MD

Average visibility in September - Gwynn Oak, 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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Gwynn Oak, Maryland, USA

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