World Resorts USA Mount Desert Island Weather

Mount Desert Island weather in September

Weather in Mount Desert Island: September

Average day temperature: 66.3°F
Average night temperature: 55.3°F
Sea water temperature: 58.4°F
Number of sunny days: 12 days
Day length: 11.8 - 13.2 hours
Number of rainy days: 2 days
Precipitation totals: 1.3 in.

Air temperature in September, °F

Show year:
2026
2025
2024

The highest day temperature during September of 2026 was 84°F. At the same time the lowest night temperature was 43°F. Daily and nightly averages during September were 66.2°F and 52.7°F.

Sea water temperature in Mount Desert Island in September, °F

Show year:
2026
2025
2024

The average sea water temperature in September of 2026 was 57.2°F. The highest and lowest sea temperatures during the month were 60.8°F and 54.9°F.

Sunny, partly cloudy and cloudy days

Number of sunny, partly cloudy and cloudy days in September is almost equal.

Precipitation total in September, in.

Precipitation total value in Mount Desert Island in September is 1.3 in. Other months of the year show relatively similar values.

Wind speed in September, mph

The average wind speed value in September is 7.0 mph It makes September one of the least windy months of the year.

Average sunny hours

This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in September is: 6.6.

Best time for vacation in Mount Desert Island

Sunniest months:
October 13 days
November 13 days
September 12 days
Warmest months:
July 73.0 °F
August 72.4 °F
June 67.2 °F
Warmest sea temp:
August 61.6 °F
July 59.6 °F
September 58.4 °F
Coldest months:
January 28.9 °F
February 30.1 °F
December 34.8 °F
Rainiest months:
December 3 days
October 3 days
March 2 days
Windiest months:
December 10.7 mph
March 10.5 mph
February 10.4 mph

Mount Desert Island on a weather map

Mount Desert Island
+45°F
E 5 mph
Feels like: +43°F
Precip.: 16%
Places in USA:
Name
°F
+54°F
+55°F
+79°F
+75°F
+75°F
+84°F
+72°F
+59°F
+73°F
+61°F
+73°F
+73°F
+75°F
+73°F
+61°F
24 Hours Forecast
Mount Desert Island
Local time: 05:17
October 09, friday
0600
45°F
E
5 mph
0900
54°F
E
8 mph
1200
59°F
E
12 mph
1500
57°F
SE
14 mph
1800
52°F
SE
12 mph
2100
46°F
E
9 mph
October 10, saturday
0000
43°F
E
8 mph
0300
43°F
E
11 mph
Units of measurement: °C / °F