Koh Phangan Weather by Month: Rain, Heat & Ferries

Featured image: Christophe95, CC BY-SA 4.0, via Wikimedia Commons.

Koh Phangan weather at a glance

Koh Phangan sits in the Gulf of Thailand, so its rain pattern differs from the Andaman coast. The Gulf side gets its heaviest rain in October and November, not in mid-year. Daily highs stay between 29°C (84°F) and 33°C (91°F) in every month. Use these four points as a quick summary.

• Driest: February, with about 4 rainy days and a median of 43 mm of rain.
• Wettest: November, with about 17 rainy days and a median of 395 mm.
• Hottest: May, with a 33°C (91°F) average high and a heat index near 41°C (106°F).
• Storm exposure: highest in November, though direct hits are rare.

Koh Phangan weather by month

This table uses Ko Samui station normals for 1991-2020, cross-checked against reanalysis data. Rainfall is the median for each month. Sea temperature stays between 28°C (82°F) and 31°C (88°F) all year, so water is never cold. Read the rainy-day column first, because it predicts disrupted plans better than millimetres do.

Dry season, shoulder months and the wet peak

February to April is the driest stretch, with 4 to 6 rainy days a month. May to September is a middle band of 10 to 11 rainy days, usually as short showers. October and November bring 16 and 17 rainy days and the heaviest totals. December is a transition month: it still logs 12 rainy days and a median of 215 mm, so do not assume clear skies. Our Koh Phangan rainy season guide covers what the wet peak means on the ground. Dry months also draw the biggest crowds. As a planning example only, a room that costs ฿1,000 in a showery month could cost ฿1,500 or more around Songkran on 13-15 April. Check live rates for your own dates.

How reliable is a dry month?

A dry month is not a guarantee. Reanalysis data for 1996-2025 shows February stayed under 60 mm in 21 of 30 years. March managed it in 14 years and April in 12. October and November never did in those 30 years. February's wettest year reached 361 mm, so pack a light rain layer even in the best weeks. Treat these counts as a Samui-calibrated proxy, not an island record.

What time of day does it rain?

Airport weather reports from Samui, about 21 km away, give a useful pattern. In November, rain falls roughly 16.9% of the time between 08:00 and 20:00. It peaks at 10:00-13:00, at 19.5% of the time. Late afternoon is slightly drier, at 14.1% from 17:00 to 20:00. Plan waterfall hikes and scooter loops for early morning, and keep a flexible indoor option for midday.

Heat, humidity and the feels-like gap

Air temperature understates the heat. In May, a 33°C (91°F) high with about 63% humidity gives a heat index near 41°C (106°F). April reaches a feels-like of about 39°C (102°F). Schedule beach walks and hikes before 10:00. Carry water, and rest in shade through the early afternoon. Lows hold at 24°C (75°F) to 26°C (79°F), so nights offer little relief without air conditioning.

Storms, monsoon seas and ferries

November is the most storm-exposed month. A tropical storm passed within 200 km in 2 of the last 35 years, and one of those reached typhoon strength. That is an exposure indicator, not a forecast. The northeast monsoon also roughens the Gulf in November and December, and some ferries run late or are cancelled on those days. There is no airport on the island. Samui airport is about 21 km away and Surat Thani airport about 117 km away. Build at least one buffer day before any flight home. Check your ferry operator's notices before you travel. Ang Thong marine park is reported closed from 1 November to 15 December in 2026, so confirm with the national park authority before booking a day trip.

Best time by activity

Match your priority to the months below. Judgements come from the rainy-day and rainfall figures above. Party fans should read about Haad Rin conditions in our Full Moon Party dates guide. A calmer alternative is the Half Moon Party Koh Phangan: Tickets, Dates & Tips, which suits a smaller crowd.

How to check the live forecast

Start with the Thai Meteorological Department for official warnings and storm bulletins. Yr is good for a 9-day table of temperature, rain and wind. A marine forecast helps most for crossings, because wave height matters more than rain. Live pages show a model grid, not an island station, so expect small differences between Haad Rin and the north coast. For party dates, use the Full Moon Party official site.

Mistakes to avoid

Three errors cause most weather-related trouble. Do not book non-refundable ferry and flight connections on tight margins in November or December. Do not plan one-shot outdoor days, since a midday downpour can cancel the whole plan. Do not ignore the heat index in April and May. For wet-month planning, read the rainy season guide before you commit to dates.