World Resorts USA Bar Harbor Weather

Bar Harbor weather in September

Weather in Bar Harbor: September

Average day temperature: 65.8°F
Average night temperature: 55.7°F
Sea water temperature: 58.4°F
Number of sunny days: 13 days
Day length: 11.8 - 13.2 hours
Number of rainy days: 2 days
Precipitation totals: 1.2 in.

Air temperature in September, °F

Show year:
2025
2024
2023

The highest day temperature during September of 2025 was 74°F. At the same time the lowest night temperature was 41°F. Daily and nightly averages during September were 65.9°F and 53.7°F.

Sea water temperature in Bar Harbor in September, °F

Show year:
2025
2024
2023

The average sea water temperature in September of 2025 was 58.5°F. The highest and lowest sea temperatures during the month were 61.2°F and 56.7°F.

Sunny, partly cloudy and cloudy days

Mostly all days in September are sunny but cloudy days are also possible.

Precipitation total in September, in.

Precipitation total value in Bar Harbor in September is 1.2 in. Other months of the year show relatively similar values.

Wind speed in September, mph

The average wind speed value in September is 7.1 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: 6.9.

Best time for vacation in Bar Harbor

Sunniest months:
September 13 days
November 13 days
October 13 days
Warmest months:
July 71.5 °F
August 71.1 °F
June 66.1 °F
Warmest sea temp:
August 61.2 °F
July 59.3 °F
September 58.4 °F
Coldest months:
January 29.4 °F
February 29.8 °F
December 35.9 °F
Rainiest months:
December 3 days
April 3 days
October 3 days
Windiest months:
February 10.9 mph
March 10.7 mph
December 10.6 mph

Bar Harbor on a weather map

Bar Harbor
+9°F
SE 21 mph
Feels like: -8°F
Precip.: 0%
Places in USA:
Name
°F
+30°F
+75°F
+75°F
+45°F
+55°F
+70°F
+77°F
+70°F
+23°F
+57°F
+48°F
+63°F
+63°F
+46°F
+5°F
24 Hours Forecast
Bar Harbor
Local time: 01:12
December 05, friday
0300
5°F
SE
17 mph
0600
3°F
SE
14 mph
0900
9°F
SE
12 mph
1200
18°F
E
11 mph
1500
23°F
E
10 mph
1800
27°F
E
6 mph
2100
25°F
E
7 mph
December 06, saturday
0000
23°F
E
5 mph
Units of measurement: °C / °F