Khao Lak weather in May
May in Khao Lak: sweltering, soaked, with clean air — a gamble, with 27 rainy days.
Updated September 2026 · climate normals from ERA5 reanalysis
#9 of 12 months in Khao Lak · #1165 of 1413 destinations to visit in May · comfort 61/100 (tier C)
- Days
- 32°C
- Nights
- 25°C
- Wet days
- 27
- Sun
- 9 h
- Humidity
- 86%
- Daylight
- 13 h

Traveller notes on Khao Lak in May
Notes from nearby Phuket (82 km away)
Khao Lak 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 Khao Lak
Regulars are specific this marks the start of the dry season here, though real residual rain remains common, any shower typically short-lived and, on a hot afternoon, genuinely welcome rather than disruptive. Our row backs that hot, genuinely wet read, 31.4C reading as a scorching 37C, over 23.6C nights feeling 28C, with a substantial 235.2mm of rain across 24.4 days and humidity at 87 percent. Regulars are consistent tours to the Similan and Surin Islands are back in full swing by this point, restaurants, bars and shops all open again after the quieter wet-season months. Multiple repeat visitors report consistently good weather in mid-November specifically across several different years. The sea sits at a bath-warm 29.8C. The record: 8.2 hours of sun, a 12.9 kph wind and AQI 31.
Regulars describe this as the tail end of dry season, hot and sunny overall, with afternoon thunderstorms becoming a real possibility as the wet season approaches - when they do arrive, they're usually short and heavy rather than sustained, and regulars note the air and even the humidity level afterward is no worse than earlier in the dry season despite the added moisture. Our row backs the building wetness, 155.7mm of rain across a real 20.8 days, alongside intense heat, 33.1C reading as a hot 40C at 81.5 percent humidity, over 24.7C nights. Regulars call this a good month for value, with online accommodation rates noticeably lower than peak season despite the weather still being broadly enjoyable. The sea holds a warm 30C. The record: 10.4 hours of sun, a 14.4 kph wind and AQI 53.
December opens the three months regulars rate highest here and they claim it is steadier than the coast further south: clear skies, calm sea, and rarely more than a short shower in a day. Some report a little rain daily and none of it lasting - which is the sense to make of our 99.1mm across 14.6 days, seven millimetres apiece. Their claim that the heat and humidity are moderate holds only against the Thai year: 31.5C at 82 percent reads as 37C, and the sea is 29C, bath water in their phrase. Peak season runs mid-December to mid-January, so the best weather and the highest prices arrive together. The record: 23.2C nights, 9.4 hours of sun and a 14.8 kph wind.
March is one of the hottest months in Khao Lak and one of the drier ones, and regulars say visitors usually welcome any rain that arrives because the heat is so high by now. Our row is the most extreme feels-like figure in this collection: 33.3C reading as 39C, with nights at 23.8C that feel like 28C. The 12.4 precipitation days look wrong against a dry month until you see the 74.5mm behind them - six millimetres a wet day, which is the odd afternoon thunderstorm they describe as the wet season approaches from early May. Seas are calm now. What the numbers make plain is that there is no relief in the water: the Andaman is 29.6C, warmer than most swimming pools. December to February is the better weather; March and April are the better value outside Songkran. The record: humidity 76 percent and 10.8 hours of sun.
Add your own note from Khao Lak's card on the map.
Khao Lak climate normals — May
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Khao Lak 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 Khao Lak'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 weatherKhao Lak's weather peaks January–March, best around February.
Best weatherFair weatherToughest weather
What's on in Khao Lak in May
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Nature
Manta and whale shark season
1 Feb – 5 May · usuallyDive seasonThe tail of the dive season at Richelieu Rock and Koh Bon, when the plankton is up and the big animals follow it. Never a sure thing, and the liveaboards sell those weeks first.
- Season
Southwest monsoon and red flags
15 May – 31 Oct · usuallyRip currents & big surfRip currents on this stretch of coast are the real risk, and the red flags go up for weeks at a time. Half the beachfront shuts and the other half drops its rates to nothing.
- Closure
Similan and Surin islands closed
16 May – 14 OctThe park authority shuts both island groups for the monsoon every year, which takes the liveaboards and the day boats out with them. Khao Lak's dive shops largely close for the season. Source ↗
- Season
Wet season
MonsoonRisk27 rainy days and about 308 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 Khao Lak — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Khao Lak?
Khao Lak in May — FAQ
- Is May a good time to visit Khao Lak?
- May in Khao Lak: sweltering, soaked, with clean air — a gamble, with 27 rainy days. It ranks #9 of 12 months for Khao Lak on SeasonMap's comfort score (61/100).
- What is the weather like in Khao Lak in May?
- In May, Khao Lak averages a daily high of 32.2°C and a low of 24.7°C, with about 307.9 mm of rain over roughly 26.7 rainy days.
- What is the air quality in Khao Lak in May?
- Khao Lak has a mean US Air Quality Index of about 33 in May.
Within 300 km: Ko Tao's Whale shark season around 15 Mar – 31 May, and Ko Samui's Gulf dry season around 15 Jan – 31 Aug.