Things to Do in Jeju in May

May is one of the more rewarding months to visit Jeju Island. The island is intensely green, temperatures are comfortable rather than oppressive, and crowds haven't yet built to the summer peak. You'll have missed the cherry blossoms and rapeseed flower carpets of March and April, but the trade-off is thinner queues at Seongsan Ilchulbong, uncongested Olle trails, and near-ideal conditions for hiking Hallasan's summit routes.

Daytime highs in May typically reach 19–22°C (66–72°F), with overnight lows around 13–16°C (55–61°F) — comfortably warm but not yet humid. Expect roughly 9–11 days with some rainfall, mostly brief showers rather than all-day downpours, as the island edges toward its June–July monsoon season. A packable rain layer is all you need; umbrellas are sold everywhere if you forget one.

May's mild temperatures make it a standout month for outdoor activity: hike the Hallasan summit via the Seongpanak or Gwaneumsa trail before summer heat sets in, walk a section of the Jeju Olle Trail along the volcanic coastline, or take the short ferry to Udo Island for its turquoise water and white-coral sand. For contrast, Manjanggul Lava Tube stays a constant 11°C year-round — a satisfying break from any warm afternoon.

By May, Jeju's hillsides and the slopes of the volcanic cones (oreum) are in deep, lush green — more saturated than during the dramatic but short-lived spring blossom period. The yellow canola fields are largely done, but the basalt coastline remains striking at spots like Jusangjeolli Cliff, and Hallasan's forested upper trails are at their most verdant. It's quieter and less photogenically famous than April, but genuinely beautiful in a calmer way.

Two Korean public holidays fall in May — Children's Day on May 5th and Buddha's Birthday (date shifts annually with the lunar calendar; confirm the 2026 date before booking) — and both drive a surge in domestic tourism to Jeju, filling hotels and pushing up prices. Outside those holiday windows, May 2026 should offer the same mild, pre-monsoon conditions as any typical May. Book accommodation at least four to six weeks out if your dates overlap with either holiday.

Hanbok rental lets you dress in traditional Korean clothing for two to three hours and explore scenic or historical sites in costume — genuinely fun and very photogenic. In Jeju, rental shops cluster near Seongup Folk Village and in pockets of Jeju City's older quarters, with fees typically running ₩20,000–₩40,000 per session (verify current prices locally). May's mild weather is one of the more comfortable months for wearing the layered garments outdoors without overheating.

Three to five days covers the island well for most visitors. Three days gets you the headline sights — Seongsan Ilchulbong, Hallasan, Manjanggul Cave, and a coastal drive — at a brisk pace. Four to five days lets you slow down, walk a longer Olle Trail section, day-trip to Udo Island, and explore the west coast around Hallim Park and Hyeopjae Beach without feeling rushed. First-timers often underestimate the island's scale: Jeju stretches roughly 73 km east to west.

June marks the start of Jeju's changma (monsoon) season, which typically arrives mid-to-late June bringing sustained humidity and heavier, more frequent rain than May's intermittent showers. Temperatures climb toward 25–28°C, and the island grows noticeably busier as Korean school summer holidays approach. If you're choosing between the two months, May wins clearly on weather, hiking conditions, and overall crowd levels.

April averages daytime highs around 15–18°C (59–64°F) — noticeably cooler than May, still jacket weather well into the afternoons. April is also peak cherry blossom and canola flower season, which draws significant crowds mid-month. May trades those famous floral spectacles for warmer, T-shirt-friendly temperatures and slightly lower tourist pressure once the blossom crowds disperse — a different but worthwhile experience.

Trazy is a South Korea-focused activity booking platform, and their Jeju taxi tour packages pair you with an English-friendly driver who covers a curated circuit of attractions — typically the east or west coast — in one full day. It's a sensible option because Jeju's public bus network is functional but slow, and many key sights sit far from town. Prices vary by route and group size; check the Trazy website for current listings and read recent traveller reviews before booking, as driver quality varies.

May is arguably the best window for summiting Hallasan: winter trail closures have lifted, summit temperatures are cool rather than bitter, and the mountain's forests are fully leafed-out in vivid green. The two main summit routes — Seongpanak (9.6 km one-way, a gentler gradient) and Gwaneumsa (8.7 km, more dramatic terrain) — each require a full day and an early start, as the Korea National Park Service enforces strict cut-off entry times to ensure hikers descend safely before dark. Check the official Korea National Park website for current gate times before you go.

May sits in a crowd sweet spot between the spring blossom rush (March–April) and the full summer surge (July–August), making it one of the calmer months at most attractions. The clear exception is the cluster of public holidays around May 5th (Children's Day) and Buddha's Birthday, when domestic tourists arrive en masse, accommodation prices spike, and popular trails see noticeably longer waits. Plan around those specific dates — or book accommodation six or more weeks ahead — and you'll find May remarkably manageable.