Portland averages 11.7 days a year above 90°F, with December the wettest month at 7.35 in of normal rain. The hottest day on record was 114°F on Jun 28, 2021; the coldest, 8°F on Feb 3, 1989. The single biggest 24-hour rain event recorded was 3.2 in on Oct 27, 1994.
Climate and Average Weather Year Round in Portland
Year-round temperature
In Portland, the warmest months are June through September, with average daily highs between 73°F and 81°F. The coldest stretch runs December through February, with highs between 46°F and 51°F and overnight lows reaching 37°F.
Rainfall through the year
Rainfall in Portland averages 3.7 in per month over the long run. December is the wettest at 7.3 in, while July is the driest at 0.4 in.
Days at 90 °F or hotter
Portland averages 11.7 days per year at 90 °F or hotter. The hottest year on record saw 21 such days (2003); the coolest just 1 (2026).
Precipitation this year
As of May 28, Portland has received 17.6 in of precipitation this year — 19% below the long-term normal for this point in the year (21.9 in).