Portland Oregon Weather September 2025. Free long range weather forecast for portland, oregon september 2025. In portland, oregon, during september, the rain falls for 10.4 days and regularly aggregates up to 1.69 (43mm) of.
The oregon state fair is almost here, along with the 2025 umpqua bank. Fall 2025 is forecast to be warmer than average for most in the u.s.