September weather forecast
Annapolis, MD

The Chesapeake Bay at dusk, in Annapolis, Maryland, with a distant view of the US Naval Academy chapel dome
The Chesapeake Bay at dusk, in Annapolis, Maryland, with a distant view of the US Naval Academy chapel dome

Weather in September

September, the first month of the autumn in Annapolis, is also a moderately hot month, with temperature in the range of an average low of 64.6°F (18.1°C) and an average high of 77°F (25°C).

Temperature

In Annapolis, the average high-temperature in September slightly decreases from 83.3°F (28.5°C) in August to a still warm 77°F (25°C). In September, in Annapolis, the average low-temperature is 64.6°F (18.1°C).

Humidity

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

Rainfall

In Annapolis, it is raining for 10.5 days, with typically 0.63" (16mm) of accumulated precipitation. In Annapolis, during the entire year, the rain falls for 120.4 days and collects up to 10.47" (266mm) of precipitation.

Snowfall

In Annapolis, Maryland, snow does not fall in April through October.

Ocean temperature

In Annapolis, Maryland, the average seawater temperature in September is 73.9°F (23.3°C).
Note: For individuals prone to feeling cold, swimming in 73.4°F (23°C) is still regarded as intolerable. A wetsuit is not a necessity, but sunshine, wind, and air temperature are essential factors for relishing swimming at 73.9°F (23.3°C).

Daylight

In Annapolis, Maryland, the average length of the day in September is 12h and 26min.
On the first day of the month, sunrise is at 6:35 am and sunset at 7:36 pm. On the last day of September, in Annapolis, Maryland, sunrise is at 7:01 am and sunset at 6:50 pm EDT.

Sunshine

The average sunshine in September in Annapolis, Maryland, 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 moderate health risk from unsafe exposure to UV radiation for the average person.
Note: The daily maximum UV index of 5 in September interpret into the following advice:
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. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.
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FAQ

What is the average humidity in September in Annapolis?

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

How many days does it rain in September in Annapolis?

In Annapolis, during September, the rain falls for 10.5 days and regularly aggregates up to 0.63" (16mm) of precipitation.

When it does not snow in Annapolis?

April through October are months without snowfall in Annapolis.

What is the ocean temperature in September in Annapolis?

In Annapolis, Maryland, in September, the average water temperature is 73.9°F (23.3°C). Depending on a person's sensitivity to cold, with regards to sunshine, wind, and air temperature, a quick swim in 73.9°F (23.3°C) water may be enjoyable.

How many hours of daylight does Annapolis have in September?

The average day length in September in Annapolis is 12h and 26min.

What time are sunrise and sunset in September in Annapolis?

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 7:01 am and sunset at 6:50 pm EDT.

How many hours of sunshine does Annapolis have in September?

In Annapolis, Maryland, the average sunshine duration in September is 9.2h.

How high is the UV index in September in Annapolis?

In Annapolis, 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 Sun's UV rays.

Average temperature in September
Annapolis, MD

Average temperature in September - Annapolis, MD
  • Average high temperature in September: 77°F

The warmest month (with the highest average high temperature) is July (84.7°F).
The month with the lowest average high temperature is January (40.3°F).

  • Average low temperature in September: 64.6°F

The month with the highest average low temperature is July (72°F).
The coldest month (with the lowest average low temperature) is January (29.8°F).

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Average pressure in September
Annapolis, MD

Average pressure in September - Annapolis, MD
  • Average pressure in September: 30.05"Hg

The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).

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Average wind speed in September
Annapolis, MD

Average wind speed in September - Annapolis, MD
  • Average wind speed in September: 7.6mph

The windiest month (with the highest average wind speed) is January (10mph).
The calmest months (with the lowest average wind speed) are July and August (6.6mph).

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Average humidity in September
Annapolis, MD

Average humidity in September - Annapolis, 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%).

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Average rainfall in September
Annapolis, MD

Average rainfall in September - Annapolis, MD
  • Average rainfall in September: 0.63"

The wettest month (with the highest rainfall) is August (1.69").
The driest month (with the least rainfall) is January (0.47").

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Average rainfall days in September
Annapolis, MD

Average rainfall days in September - Annapolis, MD
  • Average rainfall days in September: 10.5 days

The months with the highest number of rainy days are July and August (14.3 days).
The month with the least rainy days is November (5.3 days).

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Average snowfall in September
Annapolis, MD

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

The month with the highest snowfall is January (0.67").
The months with the least snowfall are April, May, June, July, August, September and October (0").

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Average snowfall days in September
Annapolis, MD

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

The month with the highest number of snowfall days is February (2.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

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Average sea temperature in September
Annapolis, MD

Average sea temperature in September - Annapolis, MD
  • Average sea temperature in September: 73.9°F

The best month for swimming (with the highest average sea temperature) is August (77.8°F).
The coldest month (with the lowest average sea temperature) is February (45.1°F).

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Average daylight in September /
Average sunshine in September
Annapolis, MD

Average daylight in September / Average sunshine in September - Annapolis, 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: 9.2h

The month with the most sunshine is July (Average sunshine: 10.8h).
The month with the least sunshine is February (Average sunshine: 5h).

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Average sunshine days in September
Annapolis, MD

Average sunshine days in September - Annapolis, MD
  • Average sunshine days in September: 17.4 days

The month with the most sunshine days is November (23.4 days).
The month with the least sunshine days is August (13.8 days).

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Average UV index in September
Annapolis, MD

Average UV index in September - Annapolis, 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 and December (UV index 2).

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Average cloud cover in September
Annapolis, MD

Average cloud cover in September - Annapolis, MD
  • Average cloud cover in September: 33

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).

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Average visibility in September
Annapolis, MD

Average visibility in September - Annapolis, 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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