September weather forecast
Prospect Harbor, ME

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Weather in September

The first month of the autumn, September, is still a refreshing month in Prospect Harbor, Maine, with an average temperature varying between 52.7°F (11.5°C) and 67.1°F (19.5°C).

Temperature

With September's onset, the weather reveals a slight temperature decrease, transitioning from a moderately hot 73.4°F (23°C) in August to an enjoyable 67.1°F (19.5°C). During September, Prospect Harbor observes a consistent average nighttime temperature of 52.7°F (11.5°C).

Humidity

In Prospect Harbor, the average relative humidity in September is 79%.

Rainfall

In September, the rain falls for 10.5 days. Throughout September, 1.81" (46mm) of precipitation is accumulated. Throughout the year, there are 142.1 rainfall days, and 32.28" (820mm) of precipitation is accumulated.

Snowfall

In Prospect Harbor, snow does not fall in June through September.

Daylight

The average length of the day in September is 12h and 30min.
On the first day of September in Prospect Harbor, sunrise is at 5:55 am and sunset at 7:08 pm. On the last day of the month, sunrise is at 6:29 am and sunset at 6:14 pm EDT.

Sunshine

In Prospect Harbor, the average sunshine in September is 8.2h.

UV index

In Prospect Harbor, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from exposure to the Sun's UV radiation for average individuals.
Note: The maximum UV index, 4 during September, leads to the following recommendations:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Updated: Aug 25, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What are the temperatures in September?

The high-temperature during September is 67.1°F (19.5°C) and the low-temperature is 52.7°F (11.5°C).

What is the average humidity in September?

In September, the average relative humidity is 79%.

How much does it rain in September?

In Prospect Harbor, in September, during 10.5 rainfall days, 1.81" (46mm) of precipitation is typically accumulated.

When it does not snow in Prospect Harbor?

June through September are months without snowfall.

Does it snow in September?

In Prospect Harbor, in September, it doesn't snow. In October, it regularly snows.

What is the average length of the day in September?

The average day length in September is 12h and 30min.

When are sunrise and sunset in September?

On the first day of September, sunrise is at 5:55 am and sunset at 7:08 pm. On the last day of the month, sunrise is at 6:29 am and sunset at 6:14 pm EDT.

How many hours of sunshine does Prospect Harbor have in September?

In Prospect Harbor, the average sunshine duration in September is 8.2h.

What is the UV index reading in September?

In Prospect Harbor, the average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate vulnerability 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
Prospect Harbor, ME

Average temperature in September - Prospect Harbor, ME
  • Average high temperature in September: 67.1°F

The warmest month (with the highest average high temperature) is August (73.4°F).
The month with the lowest average high temperature is January (29.7°F).

  • Average low temperature in September: 52.7°F

The month with the highest average low temperature is July (58.1°F).
The coldest month (with the lowest average low temperature) is January (18.5°F).

Average pressure in September
Prospect Harbor, ME

Average pressure in September - Prospect Harbor, 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
Prospect Harbor, ME

Average wind speed in September - Prospect Harbor, ME
  • Average wind speed in September: 7.1mph

The windiest month (with the highest average wind speed) is January (10.4mph).
The calmest months (with the lowest average wind speed) are July and August (6.3mph).

Average humidity in September
Prospect Harbor, ME

Average humidity in September - Prospect Harbor, ME
  • Average humidity in September: 79%

The month with the highest relative humidity is February (83%).
The month with the lowest relative humidity is November (76%).

Average rainfall in September
Prospect Harbor, ME

Average rainfall in September - Prospect Harbor, ME
  • Average rainfall in September: 1.81"

The wettest month (with the highest rainfall) is December (3.94").
The driest month (with the least rainfall) is July (1.57").

Average rainfall days in September
Prospect Harbor, ME

Average rainfall days in September - Prospect Harbor, ME
  • Average rainfall days in September: 10.5 days

The month with the highest number of rainy days is April (15.5 days).
The month with the least rainy days is February (7.5 days).

Average snowfall in September
Prospect Harbor, ME

Average snowfall in September - Prospect Harbor, ME
  • Average snowfall in September: 0"

The month with the highest snowfall is February (5.75").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days in September
Prospect Harbor, ME

Average snowfall days in September - Prospect Harbor, ME
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight in September /
Average sunshine in September
Prospect Harbor, ME

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

The month with the longest days is June (Average daylight: 15h and 30min).
The month with the shortest days is December (Average daylight: 8h and 54min).

  • Average sunshine in September: 8h and 1min

The month with the most sunshine is August (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 6min).

Average sunshine days in September
Prospect Harbor, ME

Average sunshine days in September - Prospect Harbor, ME
  • Average sunshine days in September: 17.5 days

The month with the most sunshine days is August (18.7 days).
The month with the least sunshine days is April (11.2 days).

Average UV index in September
Prospect Harbor, ME

Average UV index in September - Prospect Harbor, 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
Prospect Harbor, ME

Average cloud cover in September - Prospect Harbor, ME
  • Average cloud cover in September: 35

The month with the most cloud cover is February (Cloud cover 56).
The months with the least cloud cover are August and September (Cloud cover 35).

Average visibility in September
Prospect Harbor, ME

Average visibility in September - Prospect Harbor, ME
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).

Prospect Harbor, Maine, USA

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