September weather forecast
Brightwood, MD

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Weather in September

September, the first month of the autumn in Brightwood, is still a warm month, with temperature in the range of an average high of 77.4°F (25.2°C) and an average low of 63.3°F (17.4°C).

Temperature

Brightwood in September undergoes a slight reduction in the average high-temperature, shifting from August's moderately hot 83.7°F (28.7°C) to a still warm 77.4°F (25.2°C). During September, Brightwood records an average temperature of 63.3°F (17.4°C) at night.

Humidity

The average relative humidity in September is 75%.

Rainfall

The month with the least rainfall is September, when the rain falls for 11.8 days and typically collects 1.89" (48mm) of precipitation.

Snowfall

In Brightwood, snow does not fall in May through October.

Daylight

In Brightwood, the average length of the day in September is 12h and 26min.
On the first day of September, sunrise is at 6:35 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:50 pm EDT.

Sunshine

In Brightwood, the average sunshine in September is 9.2h.

UV index

In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for ordinary individuals.
Note: The average daily UV index of 5 in September transforms into the following instructions:
Ensure safety - Sun damage prevention is strongly urged. Direct Sun exposure should be minimized especially during midday when radiation is most intense. Safeguard your eyes, ears, and face from sun rays with the aid of a wide-brim hat.

Frequently asked questions

What are September temperatures?

The high-temperature, in September, in Brightwood, is 77.4°F (25.2°C), while the low-temperature averages to 63.3°F (17.4°C). In August, the average heat index (a.k.a. 'feels like', 'apparent temperature'), which represents the influence of relative humidity on air temperature, is calculated to be 91.4°F (33°C).

What is the average humidity in September?

The average relative humidity in September is 75%.

What is the driest month?

September is the month with the least rainfall. Rain falls for 11.8 days and accumulates 1.89" (48mm) of precipitation.

How many days does it rain in September?

In September, the rain falls for 11.8 days. Throughout September, 1.89" (48mm) of precipitation is accumulated.

When it does not snow?

In Brightwood, snow does not fall in May through October.

What is the average length of the day in September?

In Brightwood, 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 6:35 am and sunset at 7:36 pm. On the last day of the month, sunrise is at 7:02 am and sunset at 6:50 pm EDT.

How many hours of sunshine does Brightwood have in September?

In September, the average sunshine duration is 9.2h.

What is the UV index reading in September?

The average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health threat from exposure to the Sun's 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
Brightwood, MD

Average temperature in September - Brightwood, MD
  • Average high temperature in September: 77.4°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 (39.6°F).

  • Average low temperature in September: 63.3°F

The month with the highest average low temperature is July (70.7°F).
The coldest month (with the lowest average low temperature) is January (28.4°F).

Average pressure in September
Brightwood, MD

Average pressure in September - Brightwood, 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).

Average wind speed in September
Brightwood, MD

Average wind speed in September - Brightwood, MD
  • Average wind speed in September: 7mph

The windiest month (with the highest average wind speed) is March (9.4mph).
The calmest months (with the lowest average wind speed) are July and August (6mph).

Average humidity in September
Brightwood, MD

Average humidity in September - Brightwood, MD
  • Average humidity in September: 75%

The month with the highest relative humidity is May (78%).
The months with the lowest relative humidity are January, March, April and November (72%).

Average rainfall in September
Brightwood, MD

Average rainfall in September - Brightwood, MD
  • Average rainfall in September: 1.89"

The wettest month (with the highest rainfall) is August (3.54").
The driest month (with the least rainfall) is September (1.89").

Average rainfall days in September
Brightwood, MD

Average rainfall days in September - Brightwood, MD
  • Average rainfall days in September: 11.8 days

The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is November (9.4 days).

Average snowfall in September
Brightwood, MD

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

The month with the highest snowfall is January (2.05").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Brightwood, MD

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

The month with the highest number of snowfall days is January (4.4 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
Brightwood, MD

Average daylight in September / Average sunshine in September - Brightwood, 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 54min).
The month with the least sunshine is February (Average sunshine: 5h and 6min).

Average sunshine days in September
Brightwood, MD

Average sunshine days in September - Brightwood, MD
  • Average sunshine days in September: 16.4 days

The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is May (10.8 days).

Average UV index in September
Brightwood, MD

Average UV index in September - Brightwood, 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
Brightwood, MD

Average cloud cover in September - Brightwood, MD
  • Average cloud cover in September: 34

The months with the most cloud cover are February and March (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 28).

Average visibility in September
Brightwood, MD

Average visibility in September - Brightwood, 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).

Brightwood, Maryland, USA

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