United States Seattle Weather in May — Climate Guide
May in Seattle is Excellent
Seattle Weather in May — Quick Answer
As of 2026- Avg temp
- 17° / 9°
- Rainfall
- 50mm · 10 days
- Crowds
- Busy
As of 2026, Seattle in May averages a high of 17°C and low of 9°C with 50mm of rain over about 10 days. Late spring — high 17°C, low 9°C. Light layers + sunglasses + sunscreen. Long daylight; light jacket for evenings.
May is Excellent for Seattle.
May is when Seattle becomes great. Northwest Folklife Festival (Memorial Day weekend at Seattle Center) is North America's largest free folk arts festival with 5,000+ artists + 800+ acts over 4 days. Hotel rates rising toward summer peak but not yet there. Mt Rainier roads typically open by Memorial Day.
Travel score
Seattle May Weather Stats
Avg High
17°C
Avg Low
9°C
Rainy Days
10
50mm total
Sunshine
7h
Daily avg
Humidity
70%
Comfortable
UV Index
6
High
Wind
13 km/h
Gusts 28
Sea Temp
10°C
Avg water temp
Crowds
Busy
At attractions
May Sunrise & Sunset
Air Quality
PM2.5
10 μg/m³
PM10
20 μg/m³
Status
Good
Feels-Like Temperature & Wind
Feels like
Daytime
17°C
Nighttime
9°C
Humidity and wind affect how the actual temperature feels.
Wind
13 km/h
Max gust 28 km/h
Activities Recommended for May
May Travel Pros & Cons
Pros
- Dry days return (only 10 rainy)
- Northwest Folklife Festival (free)
- Mt Rainier opens
Cons
- Hotel rates climbing
- Mt Rainier trails still partial-snow
May Events & Festivals
- Northwest Folklife Festival (Memorial Day weekend, Seattle Center)
- Memorial Day (last Monday)
Seattle in May — Full Picture
May is when Seattle becomes great. Northwest Folklife Festival (Memorial Day weekend at Seattle Center) is North America's largest free folk arts festival with 5,000+ artists + 800+ acts over 4 days. Hotel rates rising toward summer peak but not yet there. Mt Rainier roads typically open by Memorial Day.
What to Wear & What to Pack
Late spring — high 17°C, low 9°C. Light layers + sunglasses + sunscreen. Long daylight; light jacket for evenings.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
Current14.3°C
6.7°C
13.3/mo
Summer (Jun·Jul·Aug)
22.7°C
12.3°C
5/mo
Autumn (Sep·Oct·Nov)
15.7°C
8°C
13/mo
Winter (Dec·Jan·Feb)
8.7°C
3.3°C
17.3/mo
Seattle Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| 8° | 3° | 18d·145mm | 2h | 80% | 1 | Quiet | Low season | |
| 10° | 4° | 16d·110mm | 3h | 78% | 2 | Quiet | Low season | |
| 12° | 5° | 16d·100mm | 4h | 75% | 3 | Moderate | Shoulder | |
| 14° | 6° | 14d·80mm | 5h | 72% | 4 | Moderate | Shoulder | |
| May (Best) | 17° | 9° | 10d·50mm | 7h | 70% | 6 | Busy | Shoulder |
| June (Best) | 20° | 11° | 8d·38mm | 8h | 68% | 7 | Very busy | Peak |
| July (peak month) (Best) | 24° | 13° | 3d·18mm | 10h | 65% | 8 | Very busy | Peak |
| August (Best) | 24° | 13° | 4d·22mm | 9h | 67% | 7 | Very busy | Peak |
| 21° | 11° | 7d·38mm | 7h | 70% | 5 | Busy | Shoulder | |
| 15° | 8° | 13d·90mm | 4h | 75% | 3 | Moderate | Shoulder | |
| 11° | 5° | 19d·175mm | 2h | 80% | 1 | Quiet | Low season | |
| 8° | 3° | 18d·145mm | 2h | 80% | 1 | Busy | Peak |
View Other Months
Seattle May Hotel Picks
Frequently Asked Questions
Is May a good time to visit Seattle?
Seattle in May is Excellent. Tourist crowds are busy and flight/hotel prices are shoulder.
What's the average temperature in Seattle in May?
Seattle May averages a high of 17°C and a low of 9°C.
Does it rain much in Seattle in May?
Seattle May averages 50mm of rainfall over about 10 rainy days.
What should I wear in Seattle in May?
Late spring — high 17°C, low 9°C. Light layers + sunglasses + sunscreen. Long daylight; light jacket for evenings.
What time are sunrise and sunset in Seattle in May?
Seattle May sunrise is 05:30 and sunset is 20:45, with 15h 15m of daylight.
What's the air quality like in Seattle in May?
Seattle May air quality (AQI) averages 35, rated Good. PM2.5 averages 10μg/m³.
What activities are recommended in Seattle in May?
In May, Seattle is great for Northwest Folklife Festival, Pike Place, Mt Rainier (limited trails).
Is May peak season in Seattle?
Seattle May crowds are busy and prices are shoulder. Advance reservations are strongly recommended.
Best Months to Visit Seattle
View Other Months
Planning a May trip to Seattle?
You've checked the weather — next come the budget and the route.
Why you can trust weather guide
Based in Chiang Mai for 8+ years, with 30+ countries visited across Southeast Asia, Japan, and Europe. Every detail in this guide is primary-source verified as of April 2026, with prices auto-refreshed via live exchange rate APIs. This isn't AI-generated boilerplate — it's written from the perspective of someone who has actually been there.