South Korea Jeju Island Weather in May — Climate Guide
May in Jeju Island is very-high
May is very-high for Jeju Island.
BEST MONTH for Hallasan azalea + Korean Children's Day family travel. Hallasan trails peak photogenic.
Travel score
Jeju Island May Weather Stats
Avg High
21°C
Avg Low
14°C
Rainy Days
9
100mm total
Sunshine
9h
Daily avg
Humidity
75%
moderate
UV Index
7
High
Wind
8 km/h
Gusts 20
Sea Temp
17°C
swimming chilly
Crowds
Very busy
At attractions
May Sunrise & Sunset
Air Quality
PM2.5
12 μg/m³
PM10
22 μg/m³
Status
good
Feels-Like Temperature & Wind
Feels like
Daytime
21°C
Nighttime
14°C
Humidity and wind affect how the actual temperature feels.
Wind
8 km/h
Max gust 20 km/h
Activities Recommended for May
May Travel Pros & Cons
Pros
- Hallasan azalea festival peak
- 21°C ideal
- Korean Children's Day
- Long daylight
Cons
- Hotels still high
- Korean honeymoon peak
May Events & Festivals
- Korean Children's Day May 5 + Buddha's Birthday (varies)
- Hallasan azalea festival late May to mid-June
Jeju Island in May — Full Picture
BEST MONTH for Hallasan azalea + Korean Children's Day family travel. Hallasan trails peak photogenic.
What to Wear & What to Pack
Warm. T-shirt + light layers.
Packing Checklist
Seasonal Weather Overview
Spring (Mar·Apr·May)
Current16.7°C
9.7°C
9/mo
Summer (Jun·Jul·Aug)
27°C
21.3°C
11.7/mo
Autumn (Sep·Oct·Nov)
21.7°C
14.3°C
7.7/mo
Winter (Dec·Jan·Feb)
9.3°C
3.3°C
7.7/mo
Jeju Island Monthly Weather Comparison
| Month | High | Low | Rain | Sun | Humid | UV | Crowd | Price |
|---|---|---|---|---|---|---|---|---|
| 8° | 2° | 8d·60mm | 5h | 65% | 2 | Quiet | Low season | |
| 9° | 3° | 8d·65mm | 6h | 68% | 3 | Quiet | Low season | |
| 12° | 5° | 9d·90mm | 7h | 70% | 5 | Moderate | Shoulder | |
| April (Best) | 17° | 10° | 9d·100mm | 8h | 70% | 6 | Very busy | Peak |
| May (Best) | 21° | 14° | 9d·100mm | 9h | 75% | 7 | Very busy | Peak |
| 24° | 18° | 11d·200mm | 6h | 80% | 8 | Moderate | Shoulder | |
| 28° | 22° | 13d·280mm | 6h | 80% | 9 | Busy | Peak | |
| 29° | 24° | 11d·200mm | 7h | 78% | 10 | Very busy | Peak | |
| 26° | 19° | 9d·200mm | 7h | 75% | 7 | Busy | Peak | |
| October (Best) | 22° | 14° | 7d·100mm | 8h | 65% | 5 | Very busy | Peak |
| November (Best) | 17° | 10° | 7d·80mm | 7h | 60% | 3 | Busy | Peak |
| 11° | 5° | 7d·50mm | 6h | 60% | 2 | Moderate | Shoulder |
View Other Months
Jeju Island May Hotel Picks
Frequently Asked Questions
Is May a good time to visit Jeju Island?
Jeju Island in May is very-high. Tourist crowds are very busy and flight/hotel prices are peak.
What's the average temperature in Jeju Island in May?
Jeju Island May averages a high of 21°C and a low of 14°C.
Does it rain much in Jeju Island in May?
Jeju Island May averages 100mm of rainfall over about 9 rainy days.
What should I wear in Jeju Island in May?
Warm. T-shirt + light layers.
What time are sunrise and sunset in Jeju Island in May?
Jeju Island May sunrise is 05:55 and sunset is 19:25, with 13h 30min of daylight.
What's the air quality like in Jeju Island in May?
Jeju Island May air quality (AQI) averages 35, rated Good. PM2.5 averages 12μg/m³.
What activities are recommended in Jeju Island in May?
In May, Jeju Island is great for Hallasan azalea trail, Seongsan, Aewol cafés.
Is May peak season in Jeju Island?
Jeju Island May crowds are very busy and prices are peak. Advance reservations are strongly recommended.
Best Months to Visit Jeju Island
View Other Months
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.