Southwest Harbor Weather in September

During September, Southwest Harbor experiences pleasant daytime temperatures of 20°C (68°F) and cooler nights around 11°C (52°F). As part of the summer season, expect quite a bit of rainfall. Around 94 mm (3.7 in) is typical.

Rainfall in Southwest Harbor in September

Climate statistics over the past 30 years suggest around 10 days of rain, with 94 mm (3.7 in) average for the month. Individual showers can be quite heavy this month. A proper umbrella or rain jacket is worth having.

Temperature in Southwest Harbor in September

Southwest Harbor in September is worth a visit. The temperature is perfect, with 20°C (68°F) during the day and 11°C (52°F) at night. The summer season is characteristic of September. Temperatures can feel cooler in the morning and evening, so layering is often the best approach. With lows of 11°C (52°F), nights are cool. If you're out after dark, an extra layer will keep you comfortable. The cooler air at night is also great for getting a good rest.

If you're a fan of comfortable temperatures and drier conditions, September is a great time to visit.

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Southwest Harbor's climate page.

Southwest Harbor Temperature in September

Min Temperature 11°C (52°F)  

Max Temperature 20°C (68°F)  

Chance of Rain 34%  

Precipitation 94 mm (3.7 in)  

Rainy days 10 days  

What to Wear in Southwest Harbor in September

For Southwest Harbor in September, you'll want flexible clothing. It's wise to pack cotton shirts, comfortable shorts, and a pair of jeans for cooler evenings. A light sweater or jacket is useful for air-conditioned spaces (like buses) or unexpected cool moments. High rain levels are expected, so pack waterproof gear and an umbrella or poncho.

What To Do in Southwest Harbor in September

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Cycling

9/10

Walking

9/10

Camping

8/10

Outdoor sports

9/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United States of America, check out our Southwest Harbor's climate page.

More climate data for Southwest Harbor

Temperature Rainfall

See the full Southwest Harbor climate overview or explore weather in the United States of America.