Two coasts, two seasons
Thailand's beach weather splits by coast. The Andaman side (Phuket, Krabi, Khao Lak) is at its best November to April. The Gulf side (Koh Samui, Koh Phangan) runs on a different cycle and is at its best roughly January to August. This means Thailand is sellable as a beach destination almost year-round — if you pick the right coast.
Bangkok works year-round: March to May is the hottest stretch (35°C+), September and October the wettest. City programmes are largely indoor-flexible either way.
Month-by-month
Booking windows
- Peak (20 Dec – 10 Jan): 8–12 weeks ahead; compulsory gala charges apply at most resorts.
- High season (Nov–Mar): 4–6 weeks ahead for preferred properties.
- Green season (May–Oct): 1–3 weeks is usually workable; strong negotiated rates.
Source-market notes
India
Year-round market with wedding and bachelor group spikes. Direct lift from all metros keeps last-minute FIT viable outside peak. November to February matches Indian holiday appetite and the Andaman season.
UK & Europe
Winter long-haul market — November to March dominates. 7 to 14-night programmes, often Bangkok + beach. Catalogue operators fix allocations up to a year out; independent agents should hold space by September for winter departures.
Gulf
Summer outbound (June–August) still works: route clients to Koh Samui for beach or keep Bangkok city + shopping-led programmes. Halal dining is widely available in Bangkok and Phuket — we maintain a vetted list.
Japan
Golden Week (late April–early May), Obon (mid-August) and year-end are the three spikes. April heat is a consideration for older travellers — build in midday breaks.
Client insists on July beach? Book Samui, not Phuket. Client insists on Phi Phi in September? Reset expectations or move the date — boat cancellations are common in rough seas.