Jeju City, on the northern coast of South Korea’s Jeju Island, has a temperate humid subtropical climate (Koppen Cfa) with four distinct seasons. Winter temperatures stay above freezing most days, while summers bring heat, humidity, and the bulk of the island’s annual rainfall. Jeju’s maritime location means it’s warmer in winter and cooler in summer than mainland Korean cities like Seoul or Busan. For more detail, see the best time to visit guide. For more, see the things to do guide.
Jeju Weather by Month: Temperature and Rainfall
Jeju City averages 1,450mm (57 inches) of rain per year, with nearly 60% falling between June and September during the East Asian monsoon (jangma). The island gets more rain than mainland Korea because moist air from the Pacific hits Hallasan Mountain and rises, cooling and releasing precipitation. Snow is rare in Jeju City itself, though Hallasan’s summit gets snow cover from December through March. For more, see the events and festivals calendar. For more, see the neighborhoods guide.
| Month | Avg High | Avg Low | Rainfall | Rain Days | Sea Temp | Sun Hours |
|---|---|---|---|---|---|---|
| January | 9°C (48°F) | 5°C (41°F) | 65mm | 11 | 14°C (57°F) | 4 |
| February | 10°C (50°F) | 6°C (43°F) | 60mm | 9 | 13°C (55°F) | 5 |
| March | 13°C (55°F) | 8°C (46°F) | 90mm | 10 | 13°C (55°F) | 6 |
| April | 18°C (64°F) | 12°C (54°F) | 95mm | 9 | 14°C (57°F) | 7 |
| May | 22°C (72°F) | 16°C (61°F) | 100mm | 9 | 16°C (61°F) | 7 |
| June | 25°C (77°F) | 20°C (68°F) | 180mm | 11 | 20°C (68°F) | 5 |
| July | 29°C (84°F) | 24°C (75°F) | 240mm | 14 | 24°C (75°F) | 5 |
| August | 30°C (86°F) | 25°C (77°F) | 260mm | 14 | 26°C (79°F) | 5 |
| September | 27°C (81°F) | 21°C (70°F) | 180mm | 10 | 24°C (75°F) | 5 |
| October | 22°C (72°F) | 16°C (61°F) | 80mm | 7 | 21°C (70°F) | 6 |
| November | 17°C (63°F) | 11°C (52°F) | 70mm | 9 | 18°C (64°F) | 5 |
| December | 12°C (54°F) | 7°C (45°F) | 55mm | 10 | 15°C (59°F) | 4 |
Jeju Winter Weather: December to February
Winter in Jeju City is mild compared to Seoul, where January lows drop to -6°C (21°F). Jeju City rarely dips below freezing even at night, though strong northwesterly winds from Siberia make it feel colder than the thermometer suggests. Wind chill can knock 3-5°C off the actual temperature. You’ll need a warm coat, hat, and gloves between December and February, but heavy snow boots aren’t necessary. Daytime highs of 9-12°C (48-54°F) mean outdoor sightseeing is comfortable if you dress in layers. This is the driest season, with just 55-65mm of monthly rain spread across roughly 10 days each month. For more, see the where to stay guide. For more, see the travel tips and FAQ.
Jeju Spring Weather: March to May
Spring transforms Jeju. March starts cool at 8-13°C (46-55°F) but warms rapidly, reaching 16-22°C (61-72°F) by May. Cherry blossoms peak in late March to early April, about a week earlier than Seoul, with Jeonnong-ro street in Jeju City becoming a tunnel of pink. Yellow canola flowers blanket the countryside from mid-March through April. Rainfall is moderate at 90-100mm per month, and the number of rain days actually dips slightly in April and May compared to March. This is the most popular season for domestic Korean tourists, so book flights and accommodation 4-6 weeks ahead. Pack a light jacket for evenings, which can still be cool through April.
Jeju Summer Weather: June to August
Summer brings the East Asian monsoon (jangma), which typically hits Jeju from late June through late July. July and August each see roughly 240-260mm of rain across 14 rainy days, often as intense downpours that last hours rather than all-day drizzle. Temperatures peak in August at 25-30°C (77-86°F) with humidity above 80%, making it feel closer to 35°C (95°F). The sea warms to a swimmable 24-26°C (75-79°F) by August. Typhoon season overlaps with late summer: Jeju is in the path of Pacific typhoons from July through September, though direct hits occur only once or twice per season on average. When typhoons do strike, they bring 24-48 hours of heavy rain, strong winds, and flight cancellations at Jeju International Airport (CJU). If you visit in summer, pack quick-dry clothing, a proper rain jacket (not just an umbrella which wind will destroy), and waterproof footwear.
Jeju Autumn Weather: September to November
September starts hot and humid at 21-27°C (70-81°F) with lingering monsoon moisture, but by October the humidity drops sharply and temperatures settle into a perfect 16-22°C (61-72°F). October is the driest month of the year with just 80mm of rain over 7 rainy days, and clear blue skies dominate. November cools to 11-17°C (52-63°F) with brilliant autumn foliage on Hallasan’s slopes. The sea remains warm enough for swimming through September (24°C/75°F) but drops quickly in October. For photographers and hikers, October and early November offer the best combination of mild temperatures, low rainfall, and golden light. This is the second-most popular season after spring, so expect higher accommodation prices in October.
