Portland Weather in May
During May, Portland experiences moderate daytime temperatures of 18°C (64°F) and cooler nights around 8°C (46°F). Expect quite a bit of rainfall. Around 108 mm (4.3 in) is typical.
Rainfall in Portland in May
Historically, the month has about 13 days of rain, averaging 108 mm (4.3 in) in total. The rain this month tends to fall in heavier spells rather than light drizzle. When it rains, showers can be significant.
Temperature in Portland in May
Daytime temperatures in Portland reach 18°C (64°F) in May, dropping to 8°C (46°F) at night. The difference between afternoon and evening temperatures is usually noticeable. Nights fall to 8°C (46°F), which is cold enough to feel it indoors too. A good thick duvet makes all the difference for a comfortable night's sleep.
Sunshine in Portland in May
Expect sunny days throughout the month, with an estimated 244 hours of sunshine. This makes it a pleasant time to visit Portland.
Average water temperature in May
At 8°C (46°F), the water is too cold for most people to swim comfortably. A wetsuit is pretty much essential if you plan to go in.If you prefer enjoying temperate temperatures and rain-free days, June, July, August and September typically offer the best circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Portland's climate page.
Portland Temperature in May
Min Temperature
8°C (46°F)
Max Temperature
18°C (64°F)
Water Temperature
8°C (46°F)
Chance of Rain
43%
Precipitation
108 mm (4.3 in)
Rainy days
13 days
Humidity
71%
Sunshine
244 hours
Percentage Sunshine
53%
Best Places in the United States of America in May
Find out more about the weather in the United States of America and which places have the best travel conditions in this month. See all of the United States of America in May →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Portland in May
For Portland in May, you'll want flexible clothing. It's wise to pack cotton shirts, comfortable shorts, and a pair of jeans for cooler evenings. A light sweater or jacket is useful for air-conditioned spaces (like buses) or unexpected cool moments. High rain levels are expected, so pack waterproof gear and an umbrella or poncho. With water temperatures around 8°C (46°F), the water is quite cold for swimming. You can skip the swimwear unless you're particularly tough. You'll definitely want to pack sunglasses and sunscreen. There will be plenty of bright sunshine this month.What To Do in Portland in May
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit the United States of America, check out our Portland's climate page.
Temperature Rainfall Sunshine Humidity Water Temp
See the full Portland climate overview or explore weather in the United States of America.
