September weather forecast
Rockland, ME

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A US flag flying outside a lighthouse on the water in Rockland, Maine
A US flag flying outside a lighthouse on the water in Rockland, Maine

Weather in September

September in Rockland, Maine signals the onset of fall, with temperatures decreasing to 63.3°F (17.4°C). The number of rainy days drops while the daylight hours gradually reduce. However, the weather remains pleasant for outdoor activities. Cloud cover begins to increase slightly, but sunshine still remains abundant, resulting in pleasant and often stunning autumn days. A distinct feature of this month is the changing foliage creating a beautiful, colorful landscape.

Temperature

A modest decline in the average high-temperature is seen during September, decreasing from an agreeable 68.7°F (20.4°C) in August to a comfortable 63.3°F (17.4°C). Rockland's September nights exhibit a subtle drop in temperature, averaging at a moderate 55.6°F (13.1°C), closely aligned with the daytime highs.

Humidity

In Rockland, the average relative humidity in September is 81%.

Rainfall

September is the month with the least rainfall. Rain falls for 10.4 days and accumulates 1.81" (46mm) of precipitation.

Snowfall

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

Ocean temperature

In Rockland, the average seawater temperature in September is 58.3°F (14.6°C).
Note: Entering waters of 58.3°F (14.6°C) is life-endangering. A mere moment in 55.4°F (13°C) waters feels piercing cold, and below 50°F (10°C) it can lead to immediate cold shock and cessation of breathing control, depending on body resilience.

Daylight

The average length of the day in September is 12h and 30min.
On the first day of September, sunrise is at 6:00 am and sunset at 7:12 pm. On the last day of the month, sunrise is at 6:33 am and sunset at 6:18 pm EDT.

Sunshine

In September, the average sunshine is 8.5h.

UV index

The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for average individuals.
Note: In September, a daily maximum UV index of 4 leads to the following instructions:
Take necessary precautions - Protection from skin and eye injury is mandatory. Avoid the Sun's strongest UV rays by seeking shade and limiting exposure during midday. 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.

Frequently asked questions

What are the temperatures in September?

In Rockland, in September, the average high-temperature is 63.3°F (17.4°C), and the average low-temperature is 55.6°F (13.1°C).

What is the average humidity in September?

In Rockland, the average relative humidity in September is 81%.

What is the driest month?

The month with the least rainfall is September, when the rain falls for 10.4 days and typically collects 1.81" (46mm) of precipitation.

How many days does it rain in September?

In Rockland, during September, the rain falls for 10.4 days and regularly aggregates up to 1.81" (46mm) of precipitation.

When it does not snow in Rockland?

May through October are months without snowfall.

What is the water temperature in September in Rockland?

In September, the average ocean temperature is 58.3°F (14.6°C). Swimming in 58.3°F (14.6°C) is considered life-threatening. Even a few minutes in 55.4°F (13°C) water is uncomfortable, and swimming below 50°F (10°C) may cause total loss of breathing control and cold shock, depending on a person's physique.

What is the average length of the day in September?

In September, the average day length is 12h and 30min.

When are sunrise and sunset in September?

On the first day of September, sunrise is at 6:00 am and sunset at 7:12 pm. On the last day of the month, sunrise is at 6:33 am and sunset at 6:18 pm EDT.

How many hours of sunshine does Rockland have in September?

In Rockland, the average sunshine duration in September is 8.5h.

What is the UV index reading in September?

The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes 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
Rockland, ME

Average temperature in September - Rockland, ME
  • Average high temperature in September: 63.3°F

The warmest month (with the highest average high temperature) is August (68.7°F).
The month with the lowest average high temperature is January (31.8°F).

  • Average low temperature in September: 55.6°F

The month with the highest average low temperature is August (60.6°F).
The coldest month (with the lowest average low temperature) is January (22.1°F).

Average pressure in September
Rockland, ME

Average pressure in September - Rockland, ME
  • Average pressure in September: 30.04"Hg

The month with the highest atmospheric pressure is September (30.04"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in September
Rockland, ME

Average wind speed in September - Rockland, ME
  • Average wind speed in September: 9.6mph

The windiest month (with the highest average wind speed) is January (14.9mph).
The calmest months (with the lowest average wind speed) are July and August (8.2mph).

Average humidity in September
Rockland, ME

Average humidity in September - Rockland, ME
  • Average humidity in September: 81%

The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is November (75%).

Average rainfall in September
Rockland, ME

Average rainfall in September - Rockland, ME
  • Average rainfall in September: 1.81"

The wettest month (with the highest rainfall) is December (3.35").
The driest month (with the least rainfall) is September (1.81").

Average rainfall days in September
Rockland, ME

Average rainfall days in September - Rockland, ME
  • Average rainfall days in September: 10.4 days

The month with the highest number of rainy days is April (15.8 days).
The month with the least rainy days is January (7.9 days).

Average snowfall in September
Rockland, ME

Average snowfall in September - Rockland, ME
  • Average snowfall in September: 0"

The month with the highest snowfall is January (2.83").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days in September
Rockland, ME

Average snowfall days in September - Rockland, ME
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (8.5 days).
The months with the least snowfall days are June, July, August, September and October (0 days).

Average sea temperature in September
Rockland, ME

Average sea temperature in September - Rockland, ME
  • Average sea temperature in September: 58.3°F

The best month for swimming (with the highest average sea temperature) is August (60.4°F).
The coldest month (with the lowest average sea temperature) is March (37.8°F).

Average daylight in September /
Average sunshine in September
Rockland, ME

Average daylight in September / Average sunshine in September - Rockland, ME
  • Average daylight in September: 12h and 3min

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 8h and 54min).

  • Average sunshine in September: 8h and 3min

The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is December (Average sunshine: 4h and 30min).

Average sunshine days in September
Rockland, ME

Average sunshine days in September - Rockland, ME
  • Average sunshine days in September: 18 days

The month with the most sunshine days is September (18 days).
The month with the least sunshine days is April (11.5 days).

Average UV index in September
Rockland, ME

Average UV index in September - Rockland, ME
  • Average UV index in September: 4

The months with the highest UV index are June, July and August (UV index 5).
The months with the lowest UV index are January, February, March, November and December (UV index 2).

Average cloud cover in September
Rockland, ME

Average cloud cover in September - Rockland, ME
  • Average cloud cover in September: 32

The month with the most cloud cover is February (Cloud cover 52).
The month with the least cloud cover is August (Cloud cover 31).

Average visibility in September
Rockland, ME

Average visibility in September - Rockland, ME
  • 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).

Rockland, Maine, USA

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