September weather forecast
Monumental, MD

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Weather in September

The first month of the autumn, September, is still a warm month in Monumental, Maryland, with temperature in the range of an average high of 77°F (25°C) and an average low of 61.3°F (16.3°C).

Temperature

With the onset of September, Monumental's average high-temperature slightly adjusts, moderately receding from August's warm 83.5°F (28.6°C) to a still moderately hot 77°F (25°C). In Monumental, September's nights observe an average temperature dip to a comfortable 61.3°F (16.3°C).

Humidity

In Monumental, the average relative humidity in September is 75%.

Rainfall

In Monumental, in September, it is raining for 13.2 days, with typically 2.24" (57mm) of accumulated precipitation. Throughout the year, in Monumental, there are 158.5 rainfall days, and 30.75" (781mm) of precipitation is accumulated.

Snowfall

In Monumental, snow does not fall in April through October.

Daylight

The average length of the day in September in Monumental 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 Monumental, the average sunshine in September is 9.2h.

UV index

In Monumental, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.
Note: The maximum UV index, 5 during September, leads to the following recommendations:
Be cautious. Those with fair skin can be subjected to burns in fewer than 30 minutes. Around midday, solar radiation is most harmful; hence, exposure should be limited. Employ a wide-brim hat for potent defense against up to 50% of UV rays.
Updated: Jul 17, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

An average high-temperature, in September, in Monumental, is 77°F (25°C) and the average low-temperature is 61.3°F (16.3°C). In August, the average heat index (a.k.a. 'real feel', 'felt air temperature'), which factors the actual air temperature with the relative humidity, is estimated at 89.6°F (32°C).

What is the average humidity in September in Monumental?

In Monumental, the average relative humidity in September is 75%.

How much does it rain in September?

In Monumental, in September, it is raining for 13.2 days, with typically 2.24" (57mm) of accumulated precipitation.

When it does not snow?

April through October are months without snowfall.

How many hours of daylight does Monumental have in September?

In September, the average day length is 12h and 26min.

When is the sunrise / sunset in September?

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, sunrise is at 7:02 am and sunset at 6:50 pm EDT.

How many hours of sunshine does Monumental have in September?

In September, the average sunshine duration is 9.2h.

How high is the UV index in September?

In Monumental, Maryland, the average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents 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
Monumental, MD

Average temperature in September - Monumental, MD
  • Average high temperature in September: 77°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 (38.5°F).

  • Average low temperature in September: 61.3°F

The month with the highest average low temperature is July (69.6°F).
The coldest month (with the lowest average low temperature) is January (27.1°F).

Average pressure in September
Monumental, MD

Average pressure in September - Monumental, 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
Monumental, MD

Average wind speed in September - Monumental, MD
  • Average wind speed in September: 6.5mph

The windiest month (with the highest average wind speed) is March (9.1mph).
The calmest months (with the lowest average wind speed) are July and August (5.7mph).

Average humidity in September
Monumental, MD

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

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

Average rainfall in September
Monumental, MD

Average rainfall in September - Monumental, 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 (1.85").

Average rainfall days in September
Monumental, MD

Average rainfall days in September - Monumental, MD
  • Average rainfall days in September: 13.2 days

The month with the highest number of rainy days is May (18.1 days).
The month with the least rainy days is November (8.4 days).

Average snowfall in September
Monumental, MD

Average snowfall in September - Monumental, 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").

Average snowfall days in September
Monumental, MD

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

The month with the highest number of snowfall days is January (4.2 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
Monumental, MD

Average daylight in September / Average sunshine in September - Monumental, 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 0min).

Average sunshine days in September
Monumental, MD

Average sunshine days in September - Monumental, MD
  • Average sunshine days in September: 14.6 days

The month with the most sunshine days is November (19.9 days).
The month with the least sunshine days is May (10.3 days).

Average UV index in September
Monumental, MD

Average UV index in September - Monumental, 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).

Average cloud cover in September
Monumental, MD

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

The month with the most cloud cover is March (Cloud cover 46).
The month with the least cloud cover is July (Cloud cover 29).

Average visibility in September
Monumental, MD

Average visibility in September - Monumental, 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).

Monumental, Maryland, USA

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