Sea Temperature in Portland in September

© Benjamin Moore

Complete information on the sea temperature range in the Atlantic Ocean in Portland in September. Historical daily data. Climate details for September. Tips on swimming conditions and beach relaxation in Portland. We find every spot where you can swim and tell you what the water temperature is there today and throughout the year.

Portland Climate and Swimming Opportunities in September

Portland lies within the Maine in United States. The average daytime temperature in Portland in September is 61°F (16°C), while the nighttime average is 49°F (9°C). There are typically 16 rainy days during the month, with a total precipitation of 3.1 inches (78 mm). The daylight duration in September in Portland is 13 hours, with an average of 4 hours of sunshine per day. The average wind speed in September is 11 mph (18 km/h), and the humidity level is around 88%.

The water temperature in Portland in September ranges from 55°F to 61°F (13°C to 16°C). At the beginning of the month, the average temperature is around 61°F (16°C), shifting to 59°F (15°C) by mid-September and reaching 59°F (15°C) in the last ten days. Overall, the average sea temperature in Portland for September is 59°F (15°C). Ideal conditions for a refreshing swim, though some may still find it a bit cool.

Frequently Asked Questions About Water Temperatures in September in Portland