Ko Lanta (Koh Lanta) weather in May
May in Ko Lanta: sweltering, soaked, with clean air — a gamble, with 27 rainy days.
Updated September 2026 · climate normals from ERA5 reanalysis
#9 of 12 months in Ko Lanta · #1119 of 1413 destinations to visit in May · comfort 64/100 (tier C)
- Days
- 32°C
- Nights
- 25°C
- Wet days
- 27
- Sun
- 9.4 h
- Humidity
- 83%
- Daylight
- 13 h

Traveller notes on Ko Lanta in May
Notes from nearby Phuket (86 km away)
Ko Lanta doesn't have its own notes for May yet — these are about Phuket, close enough to share the season.
Phuket-forum threads on May weather place it right at the start of the green season - hot and humid between showers, with posters generally expecting around an hour of rain most days rather than a full washout, and conditions described as noticeably less wet than the August-through-October stretch later in the year. Experiences vary trip to trip: some visitors report a stretch of very hot, mostly clear days, others get the more typical reliable afternoon downpour. The clearest upside is value - hotel prices drop meaningfully and the island runs far less crowded than the December-to-March high season. The one caution: posters flag rougher seas can make swimming unsafe on certain beaches, worth checking flag warnings. The record: 33.2C days feeling like a punishing 39C, 26.1C nights, a notably high 280mm across 25.4 days, 81 percent humidity, a 31.2C sea and 9.2 hours of sun.
Other months in Ko Lanta
Ko Lanta's forum confirms August is genuinely rainy season on the Andaman coast, with rough, stormy seas as much a factor as the rain itself - but experiences vary widely. One regular visitor who'd been six times including in low season said they'd only hit real rain once; another described a typical day as sunny with a quick thunderstorm rolling through in the afternoon or evening rather than a washout. Many smaller resorts close for the season from June through early November, though the mainland ferry keeps running year-round regardless.
Forum posters consistently name January and February as by far the driest, most reliable months on Koh Lanta, with several repeat visitors saying they've barely seen rain across multiple separate January/February trips - one describing a full three weeks without a drop. One visitor specifically reported a February day at 32C with not a cloud in the sky. Posters do note this isn't an absolute guarantee: some travelers have hit a rainy, overcast stretch that dampened snorkeling plans even within this generally dry window, but the clear consensus is that February sits at the reliable peak of the island's dry season.
Add your own note from Ko Lanta's card on the map.
Ko Lanta climate normals — May
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Ko Lanta in May
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
BusyLong summer break in Thailand, school holidays in 2 of the markets that fill it(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Ko Lanta's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherKo Lanta's weather peaks January–March, best around February.
Best weatherFair weatherToughest weather
What's on in Ko Lanta in May
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Season
Low-season shutdown
15 May – 15 Oct · usuallyOff-season shutdownClosuresMost of the south of the island closes, the speedboats stop and the west-coast swell takes the sand. Rates are a third of winter and the beaches are empty for a reason.
- Closure
Marine park islands closed
16 May – 31 OctThe national park shuts the smaller islands off Lanta for the rainy season, so the day trips that make the place work in winter are simply not running. Source ↗
- Season
Wet season
MonsoonRisk27 rainy days and about 288 mm in the month — the real kind of rainy season, not afternoon showers.
from the climate normals
Nearby, and something's on
Within 300 km of Ko Lanta — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Ko Lanta?
Ko Lanta in May — FAQ
- Is May a good time to visit Ko Lanta?
- May in Ko Lanta: sweltering, soaked, with clean air — a gamble, with 27 rainy days. It ranks #9 of 12 months for Ko Lanta on SeasonMap's comfort score (64/100).
- What is the weather like in Ko Lanta in May?
- In May, Ko Lanta averages a daily high of 32.1°C and a low of 24.8°C, with about 287.9 mm of rain over roughly 27.2 rainy days.
- What is the air quality in Ko Lanta in May?
- Ko Lanta has a mean US Air Quality Index of about 35 in May.
Within 300 km: Khao Lak's Manta and whale shark season around 1 Feb – 5 May, and Penang's Wesak Day on 31 May.