Weather in Portland in September
How warm is it in Portland in September?
In September the typical daytime high in Portland is 22.4 °C on average, from 24.9 °C at the start to 19.5 °C at the end of the month.
That is 4.0 °C cooler than in August and 6.4 °C warmer than in October.
The last 10 years were 1.5 °C warmer than more than 40 years ago.
Click a day for more: afternoon and night, the usual range, records and how fast it is warming.
The average of the weather stations Gardiner (73 km), Nashua (138 km) and Blue Hill Coop (175 km); nearer ones count more.