WeatherArchive / Climate averages / Portland
Portland weather by month: climate averages
Portland averages 54°F (12°C) over the year. August is warmest, with highs around 82°F (28°C); February is coldest, with lows near 35°F (2°C). About 50 inches (1280 mm) of precipitation falls on roughly 146 days a year, from 30 years of ERA5 data (1996–2025).
| Month | Avg high | Avg low | Precip. | Days ≥1 mm | Sunshine / day |
|---|---|---|---|---|---|
| January | 8.1°C | 1.8°C | 179.6 mm | 17.6 | 4.5 h |
| February | 9.5°C | 1.8°C | 136.3 mm | 15.6 | 6.0 h |
| March | 12.0°C | 3.4°C | 148.1 mm | 18.2 | 7.3 h |
| April | 14.8°C | 5.2°C | 109.1 mm | 15.3 | 9.4 h |
| May | 18.6°C | 8.5°C | 77.1 mm | 11.7 | 10.5 h |
| June | 22.2°C | 11.4°C | 48.2 mm | 7.3 | 11.8 h |
| July | 27.6°C | 14.2°C | 9.2 mm | 2.1 | 13.3 h |
| August | 27.9°C | 14.8°C | 15.3 mm | 2.7 | 12.2 h |
| September | 23.9°C | 12.3°C | 49.8 mm | 6.7 | 10.4 h |
| October | 16.8°C | 8.2°C | 113.6 mm | 12.5 | 7.3 h |
| November | 11.0°C | 4.4°C | 184.1 mm | 17.3 | 5.1 h |
| December | 7.7°C | 2.0°C | 209.3 mm | 18.6 | 4.0 h |
Record high 1996–2025: 46.0°C on 2021-06-28. Record low: -15.3°C on 1996-02-02.
Source: Open-Meteo Historical Weather API (CC BY 4.0). Values are ERA5 reanalysis model data on a ~9–25 km grid, not readings from a weather station, so a single town’s thermometer can differ by a few degrees and local showers can be missed. Grid cell 45.52, -122.64 at 25 m. For snowfall, humidity and a best-time-to-visit score, open Portland in the climate tool.
Portland weather month by month
The wettest month in Portland is December, averaging 8.2 in (209 mm); the driest is July at 0.4 in (9 mm). December has the most days with at least 1 mm of rain (about 19). July is the sunniest month, with about 13.3 hours of sunshine a day, against 4.0 hours in December. If you like average highs between 64 °F and 82 °F (18–28 °C) with few rainy days, aim for July, August and September.
Planning a particular day? See how often that date was wet or hot over 30 years with the event weather odds, or look up what the weather actually was on any past date in the historical weather archive.
Questions people ask
What is the warmest month in Portland?
August, with an average daily high of 82°F (28°C) over 1996–2025.
What is the coldest month in Portland?
February, when nights average about 35°F (2°C).
What is the rainiest month in Portland?
December has the most precipitation (about 8.2 in (209 mm)), and December has the most rainy days (about 19 days with 1 mm or more). The driest month is July.
How much sunshine does Portland get?
About 8.5 hours of bright sunshine a day averaged over the year, from 4.0 h in December to 13.3 h in July. Sunshine here is the model’s estimate of hours with direct sun, not hours of daylight.
What is the best month to visit Portland for mild weather?
By average high between 64 °F and 82 °F (18–28 °C) and the fewest rainy days: July, August, September. Prices, crowds and events are not included.