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Portland’s climate is mild for much of the year, but the rainfall is what you’ll notice first. The city averages 915mm (36 inches) of rain a year, most of it falling between October and May, while summer stretches from June to September are notably dry. Average highs range from 8°C (46°F) in December and January to 27°C (81°F) in July and August. Snow is rare in the city itself, usually under 10cm (4 inches) in a season, and it often melts within a day. This Portland weather by month breakdown gives you exact numbers for planning. For best time to visit Portland, see our best time to visit Portland.
Portland Weather by Month: January to March
January is the coldest month, with an average high of 8°C (46°F) and a low of 3°C (37°F). Expect around 124mm (4.9 inches) of rain across 18 wet days. February is similar, warming slightly to 10°C (50°F) highs with about 101mm (4 inches) of rain. March brings the first hints of spring: highs reach 13°C (56°F), lows sit at 4°C (40°F), and rainfall eases to about 93mm (3.7 inches). Overcast skies dominate, and you’ll want a waterproof jacket for all three months. The sun appears on roughly a third of days. For things to do in Portland, see our things to do in Portland.
Portland Weather by Month: April to June
April is a turning point. Highs climb to 16°C (61°F) and rainfall drops to about 60mm (2.4 inches). May sees highs near 19°C (67°F) and is one of the best months to visit, with rain falling to about 48mm (1.9 inches) across 12 days. June is the start of true dry season, with highs of 22°C (72°F), lows of 11°C (52°F), and just 34mm (1.3 inches) of rain. June is also the month of the Rose Festival, when the city’s rose gardens are in full bloom. For Portland events and festivals, see our Portland events and festivals.
Portland Weather by Month: July to September
July and August are the warmest and driest months. July averages 27°C (81°F) during the day and 14°C (57°F) at night, with only 13mm (0.5 inches) of rain. August is nearly identical, averaging 27°C (81°F) highs and just 17mm (0.7 inches) of rain. Heat waves push temperatures above 32°C (90°F) a few times each summer, and most homes lack air conditioning, so plan indoor activities for mid-afternoon. September stays warm at 24°C (75°F) and dry at 33mm (1.3 inches), making it a quieter extension of summer. For best neighborhoods in Portland, see our best neighborhoods in Portland.
Portland Weather by Month: October to December
October signals the return of rain, averaging 69mm (2.7 inches) with highs of 18°C (64°F). November jumps to 142mm (5.6 inches) of rain and highs of 11°C (52°F), the wettest month of the year by some counts. December averages 115mm (4.5 inches) of rain, highs of 8°C (46°F), and lows near 2°C (36°F). Snow occasionally falls in December and January but rarely sticks. For help choosing timing, see our {link(‘portland-best-time-to-visit’, ‘best time to visit Portland’)} guide. For where to stay in Portland, see our where to stay in Portland.
Average monthly highs, lows, and rainfall: For Portland travel tips, see our Portland travel tips.
| Month | High (°C) | Low (°C) | Rain (mm) |
|---|---|---|---|
| January | 8 | 3 | 124 |
| February | 10 | 4 | 101 |
| March | 13 | 4 | 93 |
| April | 16 | 6 | 60 |
| May | 19 | 9 | 48 |
| June | 22 | 11 | 34 |
| July | 27 | 14 | 13 |
| August | 27 | 14 | 17 |
| September | 24 | 12 | 33 |
| October | 18 | 8 | 69 |
| November | 11 | 5 | 142 |
| December | 8 | 2 | 115 |
Portland Weather by Month: Humidity, Sunshine, and Snow
Relative humidity is high year-round, typically 70 percent to 80 percent, driven by the nearby Pacific. Sunshine averages 2,340 hours a year but is unevenly spread: July and August deliver 300-plus hours each, while December sees under 60. Snowfall averages 11cm (4.3 inches) annually, almost all in December, January, and February, and it rarely accumulates for more than a day. Portland sits about 80km (50 miles) inland from the coast and roughly 105km (65 miles) east of Mount Hood, which keeps it warmer than coastal towns but cooler than the high desert.
