30YearWeather
Portland in May
Portland weather in May - United States
🌤️Mild & Comfortable

Portland Weather in May

Plan your May trip to Portland, United States. Based on 30 years of NASA data, expect temperatures of 19°C (high) to 9°C (low), with 28% rain probability and 8 hours of daily sunshine. Pack rain gear for around 18 rainy days.

Avg High
19°C

Hottest around day 31

Avg Low
9°C

Coolest around day 1

Rainy Days
18days

28% avg rain chance

Sunshine
8hrs/day

Spring season

Portland May Weather Calendar

Click any day to see detailed weather information

Currency

USD

$ United States dollar

Language

English

Driving

Right side

Safety

Moderate Safety

GPI: 2.44

Travel Intelligence

Exclusive flight analytics & health data for Portland

Smart Flight Estimator

Airport-to-Airport Logistics

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Flight Connectivity Analysis

Airport traffic data & seasonal patterns

Well Connected
62/ 100
Traffic Index

Popular destination

Peak Daily Arrivals

0

slots per day

Peak

Aug

Low

Jan

Monthly Traffic Distribution

203
Jan
204
Feb
225
Mar
256
Apr
287
May
297
Jun
324
Jul
326
Aug
305
Sep
275
Oct
209
Nov
253
Dec
Traffic Level
Low Season

Key Connections

Seattle Tacoma (SEA)
Los Angeles (LAX)
Denver (DEN)
Phoenix Sky Harbor (PHX)
San Francisco (SFO)

Health & Safety Advisory

CDC travel health recommendations

No Requirements

No Special Vaccinations Required

Standard travel precautions apply

Source: CDC Travelers' Health

View Complete Health Guide

Is May a Good Time to Visit Portland?

👍Very good conditions overall
Short Answer

Portland's May delivers on its reputation: 19°C, 28% rain, 10.2h sunshine. The trade-off? Peak crowds and prices at 88% capacity.

Decision Factors

Peak tourist season

88% of annual peak - expect crowds and high prices

Near active volcano: Mount St. Helens

Medium volcanic risk

Plenty of sunshine

10.2h of sunshine daily

Good For

  • 👨‍👩‍👧‍👦
    Families with children

    Comfortable 18.8°C temperatures and low 28% rain risk

  • 👴
    Elderly travelers

    Comfortable 18.8°C temperature range with manageable humidity

  • 🏛️
    Cultural tourists

    Comfortable conditions for exploring museums and sites

  • 💼
    Business travelers

    Climate-controlled meetings unaffected by weather

  • 🌡️
    Heat-sensitive visitors

    Manageable 18.8°C without oppressive humidity

Who Should Avoid

  • 💰
    Budget travelers

    Peak season means premium prices everywhere

930 observations30-year historical data
Confidence: 95%

"According to 30YearWeather's analysis of 30 years of NASA POWER satellite data,Portland in May averages 19°C with 28% precipitation probability."

📊 Source: 30YearWeather.com🛰️ Data: NASA POWER (1991-2021)View Methodology →

Frequently Asked Questions: Portland in May

What are the temperatures in Portland in May?

Daytime highs average 19°C, nights drop to 9°C. Temperatures remain fairly consistent.

How many rainy days in Portland in May?

Expect around 18 days with measurable rainfall. Rain is unlikely to disrupt plans.

What to wear in Portland in May?

Layers are key. A medium-weight jacket and closed-toe shoes.

Is May peak season in Portland?

This is shoulder season—moderate prices and manageable crowds.