September Weather in Southwest Harbor

Last updated: March 2, 2024

The weather in Southwest Harbor, United States, during September is characterized by an average temperature of 15°C (59°F). Highs can soar to 18°C (65°F), while lows may dip to 11°C (52°F). Typically, the humidity level in Southwest Harbor throughout September hovers around 77%.

11°C (52°F)

Minimum temperature

15°C (59°F)

Average temperature

18°C (65°F)

Maximum temperature

77%

Humidity

Precipitation and Sunshine hours

In September, Southwest Harbor averages 105 mm (4.2 inches) of rainfall, typically over the course of 9 rainy days. The month enjoys an average of 12 hours 27 minutes of daylight, with the sun shining for approximately 9 hours 22 minutes each day. Additionally, there is a 41% probability of sunny days during this period.

105 mm (4.2 inches)

Precipitation

9 rainy days

Rainy days

9 hours 22 minutes

Sunshine hours

41%

Chance of sun

UV Index

In September, the UV Index in Southwest Harbor reaches a maximum of 7, indicating a level of High exposure. The most intense UV radiation typically occurs between 12:00 and 14:00, during which unprotected skin may burn in as little as 25 minutes.

Average solar exposure data for the current time of the year. Actual values may vary and depend on many factors, such as cloud cover, vegetation cover, surface type, etc.
  07:00 08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00 16:00 17:00 18:00 19:00
UVI 1 2 3 5 6 7 7 6 4 3 1 1 0
Exposure Low Moderate High Moderate Low
Time to burn 45 min 30 min 25 min 30 min 45 min

Compare Southwest Harbor's Climate with Cities Worldwide