Jeju is a volcanic island off South Korea's south coast with genuinely distinct seasons — the trade-off is between mild, colorful shoulder seasons and a summer that brings both the warmest weather and the region's typhoon risk.
April to May: cherry blossoms, canola fields, and mild weather
Spring temperatures climb from around 10°C into the low-to-mid 20s°C (50s to mid-70s°F) across these two months, with April in particular known for cherry blossoms and Jeju's famous bright-yellow canola flower fields — among the island's most photographed sights. This is widely considered one of the two best windows to visit, combining comfortable weather with the island at its most colorful.
June to September: warm, wet, and typhoon-prone
Summer brings the warmest temperatures of the year, with July and August averaging around 27-30°C (80-86°F), but it's also the rainiest stretch, with monthly rainfall roughly two to three times higher than the shoulder seasons. Typhoon season runs from July into early October, with occasional storms possible from late June — this is the one real planning risk on Jeju, and it's worth keeping travel dates flexible or insured if you're visiting in this window.
Mid-October to mid-November: the other sweet spot
Autumn brings temperatures back down to a comfortable high-teens-to-low-20s°C (60s to low 70s°F) range, typhoon risk drops off, and the island's volcanic landscape — including Hallasan, South Korea's tallest mountain — moves into its own foliage season. Along with spring, this is the window most consistently recommended as Jeju's best.
December to March: cold but mild by Korean standards
Winter temperatures typically sit between about 4°C and 10°C (high 30s to low 50s°F) — noticeably milder than mainland Korea thanks to Jeju's coastal, subtropical-leaning climate, though still cool enough that it's not a beach season. It's a quiet time to see the island's volcanic cones and coastline without crowds.
Practical notes
- Typhoon season (roughly July–early October, peaking August–September) is the main variable to plan around — check forecasts close to departure and keep accommodation flexible if traveling then
- Jeju is reached almost entirely by domestic flights from Seoul or Busan, or by ferry — factor a connection into your itinerary rather than expecting a direct international flight
- Korean public holidays like Chuseok (the autumn harvest festival) drive heavy domestic travel to Jeju and push both flight and accommodation prices up sharply
- Hallasan's summit trails can close seasonally or due to weather — check current access before planning a hike around it
The short version
April–May and mid-October–mid-November are Jeju's two standout windows, offering the best combination of comfortable weather, low typhoon risk, and seasonal scenery. Summer (June–September) is warmest but comes with real typhoon risk, and winter is mild by Korean standards but too cool for the beach.