Thailand in September
Weather, where to go and what is on — then plan the whole trip, door to door.
The weather in September
Often the wettest month. Andaman seas are at their roughest, so ferries can be cancelled at short notice; keep a spare day before your flight home.
A general pattern, not a forecast: weather changes from year to year, and festivals that follow the moon move by a few weeks.
Good to go in September
Ayutthaya
Central
The old royal capital (UNESCO World Heritage): temple ruins by bicycle, an easy trip north of Bangkok.
Bangkok
Central
Capital: temples, street food, markets, rooftop bars.
Chiang Mai
North
Old city temples, night markets, mountains and elephant sanctuaries.
Chiang Rai
North
Northern city of striking modern temples — the White Temple and Blue Temple — and the Golden Triangle.
Hua Hin
Gulf coast
The royal seaside town: a long beach, night markets, seafood and Sam Roi Yot's famous cave pavilion — 3–4 hours from Bangkok.
Kanchanaburi
West
The Bridge on the River Kwai, the Death Railway and Erawan's turquoise waterfalls — 2–3 hours west of Bangkok.
Koh Phangan
Gulf islands
Laid-back island between Samui and Koh Tao — remote beaches, jungle waterfalls and the Full Moon Party at Haad Rin.
Koh Samui
Gulf islands
Palm-fringed Gulf island with its own airport: Chaweng and Lamai beaches, Fisherman's Village and Ang Thong marine park.
Koh Tao
Gulf islands
Small island famous for diving, snorkelling and viewpoints.
Pai
North
Mountain valley town north-west of Chiang Mai: canyon sunsets, waterfalls, hot springs and a nightly walking street.
Pattaya
East
Busy beach city 2 hours from Bangkok: Walking Street nightlife, the wooden Sanctuary of Truth and day trips to Koh Larn.
Sukhothai
North
Thailand's first capital (UNESCO World Heritage): lotus ponds and Buddha statues among ruins, best explored by bicycle.
Season to know about
Still possible — we show these notes on the legs of your plan and keep a spare day where ferries may stop.
- Khao Lak
Southwest monsoon on the Andaman side (usually May–Oct): rain and rough seas — boats can be cancelled at short notice; keep a spare day before your flight. Sample pattern — operator to confirm.
- Khao Sok
Rainy season (usually Jun–Oct): trails get muddy and leeches come out; the lake is still beautiful.
- Koh Chang
Rainy season on the east coast (usually Jun–Oct): heavy showers and rougher seas; some boat trips stop.
- Koh Lanta
Southwest monsoon on the Andaman side (usually May–Oct): rain and rough seas — boats can be cancelled at short notice; keep a spare day before your flight. Sample pattern — operator to confirm.
- Koh Lipe
Monsoon (usually May–Oct): fewer boats, rough crossings and some places close.
- Koh Phi Phi
Southwest monsoon on the Andaman side (usually May–Oct): rain and rough seas; boat trips and some ferries stop on bad days.
- Koh Samet
Rainy season on the east coast (usually Jun–Oct): heavy showers and rougher seas; some boat trips stop.
- Krabi
Southwest monsoon on the Andaman side (usually May–Oct): rain and rougher seas; some island boat trips stop.
- Phuket
Southwest monsoon on the Andaman side (usually May–Oct): rain and rougher seas; some island boat trips stop.
Festivals and events
Phuket Vegetarian Festival
September or October, nine days (moves with the moon) · Phuket Town
Travel in September
Pick your dates and places: we plan the flight in, transfers, stays, every connection and the flight home — booked together in one checkout.