Weather by month
Koh Samui in May 2027
May on Koh Samui usually mixes sunny spells with showers. Rain often comes in short bursts, so most days still have time for the beach.
May at a glance
- Average high
- 32.9 °C
- Average low
- 25.7 °C
- Rainfall
- 132 mm
- Rain days
- 11.0 days
21% less rain than an average month
Averages: WMO Climate Normals 1991–2020, Ko Samui (station 48550, Thai Meteorological Department observations), as published on Wikipedia (secondary source, checked 7 Nov 2026). Not a forecast — for warnings use the Thai Meteorological Department. TMD weather warnings
Season verdict
Mixed — sunny spells and showers; good for most plans with a flexible day.
Good for
Beach mornings, temples and markets, spa and cooking classes, flexible boat trips
Less good for
Fixed-date boat trips without a backup day
Sea & boat trips
Outside the northeast monsoon the sea is calmer more often, but wind and waves still change day to day. Always check the operator before a boat trip.
Open or closed
Ang Thong Marine National Park is usually open in May. Trips still depend on the sea on the day. Park information
Holidays & alcohol-sale bans in May 2027
- Visakha Bucha20 May 2027Alcohol-sale ban
Full holiday calendar · Dates: Bank of Thailand holiday notifications and Thai press; check before you travel.
Events in May
- Lamai Night Plaza (daily)13 dates from 1 May 2027
- Nathon Night Food Market (daily)13 dates from 1 May 2027
- Chaweng Night Market / Food Village (daily)13 dates from 1 May 2027
- ARKbar Fire Show13 dates from 1 May 2027
- Lamai Sunday Walking Street2 dates from 2 May 2027
- Muay Thai Fight Night — Samui International Stadium5 dates from 2 May 2027
- Fisherman's Village Walking Street (Friday)1 date from 7 May 2027
What to pack
Sun protection plus a light rain jacket or poncho, and a dry bag for boat days.
One next step
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