Unseasonably hot start to September for the Portland metro

PORTLAND, Ore. (KOIN) -- Labor Day was the unofficial end to summer, but some of the hottest heat of the season could occur around Portland this week.

Summer heat returns to Oregon and Washington in a big way for the first full week of September. Afternoon highs could potentially break records that have been in place for more than 60 years. This comes as Portland's forecast highs near the century mark Thursday and Friday.

The high heat comes as a ridge of high pressure builds over the western half of the country. September's first week of high heat could be some of the warmest temperatures felt all summer long. Despite meteorological fall starting September 1, astronomical autumn doesn't start until the later in the month.

On average, Portland sees nearly a 10-degree temperature drop over the month of September. This comes as the the number of daylight hours shrinks by nearly 90 minutes over the next four weeks.