September weather forecast
Chevy Chase, MD

Weather in September

September, the first month of the autumn in Chevy Chase, is also a moderately hot month, with an average temperature varying between 78.4°F (25.8°C) and 61.5°F (16.4°C).

Temperature

In Chevy Chase, Maryland, the average high-temperature in September marginally drops from 85.8°F (29.9°C) in August to a still moderately hot 78.4°F (25.8°C). In Chevy Chase, the average low-temperature is 61.5°F (16.4°C).

Humidity

The average relative humidity in September is 73%.

Rainfall

In September, in Chevy Chase, the rain falls for 12.5 days. Throughout September, 2.05" (52mm) of precipitation is accumulated. Throughout the year, in Chevy Chase, there are 150.3 rainfall days, and 28.66" (728mm) of precipitation is accumulated.

Snowfall

In Chevy Chase, Maryland, snow does not fall in May through October.

Daylight

In Chevy Chase, 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 7:39 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:53 pm EDT.

Sunshine

The average sunshine in September is 8.8h.

UV index

In Chevy Chase, the average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for ordinary individuals.
Note: In September, the average maximum UV index of 5 translate into the following recommendations:
Take precautions - Protection against sun damage is advised. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
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FAQ

What is the temperature in September in Chevy Chase?

In Chevy Chase, in September, the average high-temperature is 78.4°F (25.8°C), and the average low-temperature is 61.5°F (16.4°C). in August, the average heat index (a.k.a. 'apparent temperature', 'feels like'), which factors the actual air temperature with the relative humidity, is estimated at 95°F (35°C).

What is the average humidity in September in Chevy Chase?

The average relative humidity in September in Chevy Chase, Maryland, is 73%.

How much does it rain in Chevy Chase in September?

In Chevy Chase, Maryland, in September, during 12.5 rainfall days, 2.05" (52mm) of precipitation is typically accumulated.

When it does not snow in Chevy Chase?

In Chevy Chase, snow does not fall in May through October.

How many hours of daylight does Chevy Chase have in September?

In September, the average day length in Chevy Chase, Maryland, is 12h and 26min.

When is the sunrise / sunset in September in Chevy Chase?

On the first day of September in Chevy Chase, Maryland, sunrise is at 6:37 am and sunset at 7:39 pm. On the last day of the month, sunrise is at 7:03 am and sunset at 6:53 pm EDT.

How long on average sun shines in September in Chevy Chase?

The average sunshine duration in September in Chevy Chase, Maryland, is 8.8h.

How high is the UV index in September in Chevy Chase?

The average daily maximum UV index in September is 5. A UV Index estimate 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 sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Chevy Chase, MD

Average temperature in September - Chevy Chase, MD
  • Average high temperature in September: 78.4°F

The warmest month (with the highest average high temperature) is July (87.8°F).
The month with the lowest average high temperature is January (39.9°F).

  • Average low temperature in September: 61.5°F

The month with the highest average low temperature is July (69.4°F).
The coldest month (with the lowest average low temperature) is January (27°F).

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Average pressure in September
Chevy Chase, MD

Average pressure in September - Chevy Chase, 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).

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Average wind speed in September
Chevy Chase, MD

Average wind speed in September - Chevy Chase, MD
  • Average wind speed in September: 5.7mph

The windiest month (with the highest average wind speed) is March (8mph).
The calmest month (with the lowest average wind speed) is August (5.1mph).

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Average humidity in September
Chevy Chase, MD

Average humidity in September - Chevy Chase, MD
  • Average humidity in September: 73%

The month with the highest relative humidity is December (76%).
The month with the lowest relative humidity is July (69%).

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Average rainfall in September
Chevy Chase, MD

Average rainfall in September - Chevy Chase, MD
  • Average rainfall in September: 2.05"

The wettest month (with the highest rainfall) is August (3.82").
The driest month (with the least rainfall) is January (1.69").

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Average rainfall days in September
Chevy Chase, MD

Average rainfall days in September - Chevy Chase, MD
  • Average rainfall days in September: 12.5 days

The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is November (8.5 days).

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Average snowfall in September
Chevy Chase, MD

Average snowfall in September - Chevy Chase, MD
  • Average snowfall in September: 0"

The month with the highest snowfall is January (2.6").
The months with the least snowfall are May, June, July, August, September and October (0").

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Average snowfall days in September
Chevy Chase, MD

Average snowfall days in September - Chevy Chase, MD
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (4.4 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

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Average daylight in September /
Average sunshine in September
Chevy Chase, MD

Average daylight in September / Average sunshine in September - Chevy Chase, MD
  • Average daylight in September: 12h and 26min

The month with the longest days is June (Average daylight: 14h and 52min).
The month with the shortest days is December (Average daylight: 9h and 29min).

  • Average sunshine in September: 8h and 48min

The month with the most sunshine is July (Average sunshine: 10h and 42min).
The months with the least sunshine are January, February and December (Average sunshine: 5h and 0min).

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Average sunshine days in September
Chevy Chase, MD

Average sunshine days in September - Chevy Chase, MD
  • Average sunshine days in September: 15.8 days

The month with the most sunshine days is November (20.4 days).
The months with the least sunshine days are May and July (12.3 days).

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Average UV index in September
Chevy Chase, MD

Average UV index in September - Chevy Chase, 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
Chevy Chase, MD

Average cloud cover in September - Chevy Chase, 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).

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Average visibility in September
Chevy Chase, MD

Average visibility in September - Chevy Chase, 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).

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