Thailand: Two Coasts, and the Month I Nearly Ruined
I booked a November island trip to the wrong coast, discovered the two sides run on opposite seasons, and rebooked everything from a Bangkok hostel.
Departures Diary Editorial
August 15, 2026 · 3 min read
Key takeaways
- November is the single wettest month on Koh Samui and one of the first good months on the Andaman side.
- My plan had Chiang Mai in March, which every season chart described as dry and pleasant.
- Roughly 48,500 baht, about $1,350, for a month in private rooms throughout.
- Andaman (west): Phuket, Krabi, Lanta, Phi Phi — Nov–Apr — May–Oct.
- Gulf (east): Samui, Phangan, Tao — Jan–Aug — November.
I booked flights into Bangkok for mid-November and accommodation on Koh Samui for the first week, because I wanted islands and November sounded like dry season. It is, on the other side of the country.
The two coasts
Thailand's islands sit on two coasts with opposite weather cycles, and nobody had mentioned this in anything I read.
| Coast | Islands | Best | Worst |
|---|---|---|---|
| Andaman (west) | Phuket, Krabi, Lanta, Phi Phi | Nov–Apr | May–Oct |
| Gulf (east) | Samui, Phangan, Tao | Jan–Aug | November |
November is the single wettest month on Koh Samui and one of the first good months on the Andaman side. I had booked precisely the wrong island for precisely the wrong week.
I found this out in a Bangkok hostel from someone who had just come back soaked. I cancelled Samui, lost a deposit, and went to Koh Lanta instead. Lanta in late November was perfect.
The other seasonal trap
My plan had Chiang Mai in March, which every season chart described as dry and pleasant.
It is dry. It is also burning season — February to April — when agricultural burning across the north pushes air quality in Chiang Mai to among the worst readings globally. Some days the mountains around the city are simply not visible.
I moved the north to the start of the trip, in late November, and it was clear and cool. Anyone with asthma should treat March in northern Thailand as a hard no rather than a caveat.
What the month looked like
Bangkok, four days. One district per day rather than crossing the city. The Grand Palace early, Chinatown after dark for the street kitchens, and Bang Krachao — the undeveloped island in a loop of the river, reached by a ten-minute boat and cycled on raised concrete paths through jungle. Almost no visitors and the best half-day in the city.
Chiang Mai and the Mae Hong Son loop, eight days. The loop is 600 km of mountain road over four days through Pai and Mae Hong Son. I split a rental car with two people from the hostel — about 4,000 baht including fuel for the four days. Most people ride it on motorbikes; two in our hostel came off theirs that week, and travel insurance generally excludes motorbike accidents without the right licence.
Koh Lanta, nine days. The best value Andaman island — calmer than Phi Phi, cheaper than Phuket, long beaches, and bungalows at 500–900 baht.
Isaan, six days. The northeast, which almost no foreign visitors reach. Khmer temple ruins at Phanom Rung, the Mekong towns, and the best food in Thailand at prices set by local wages rather than tourism.
What it cost
| Item | 30 days |
|---|---|
| Accommodation (private rooms) | THB 21,000 |
| Food | THB 12,500 |
| Transport including trains and ferries | THB 8,500 |
| Car share, Mae Hong Son loop | THB 1,400 |
| Activities and entries | THB 5,000 |
Roughly 48,500 baht, about $1,350, for a month in private rooms throughout.
The lines that would have blown it: island ferry hopping if I had done more of it, beachfront restaurants rather than walking two streets inland, and bar districts.
The lesson
Check which coast before booking anything. It is one sentence and it would have saved me a deposit and a week.
Frequently asked questions
Do Thailand's two coasts have different seasons?
Yes, and it is the most useful fact in Thai trip planning. The Andaman coast — Phuket, Krabi, Koh Lanta — is best November to April. The Gulf coast — Koh Samui, Koh Phangan, Koh Tao — is best January to August and is wettest in November, precisely when the Andaman side is entering its best months.
When should you avoid northern Thailand?
February to April, when agricultural burning pushes air quality in Chiang Mai and the surrounding provinces to among the worst readings in the world. It is dry and therefore appears on season charts as a good time to visit, which makes it a common and unpleasant surprise for people with any respiratory sensitivity.
How much does a month in Thailand cost?
Roughly $900 to $1,400 for a month covering private rooms, mostly local food and overland transport, though the islands in high season push that up substantially. The north and Isaan are the cheapest regions and Phuket and Phi Phi in January the most expensive by a wide margin.
Is the Mae Hong Son loop worth doing?
It is the best thing in northern Thailand — roughly 600 kilometres of mountain road over four days from Chiang Mai through Pai and Mae Hong Son. Doing it by car rather than motorbike is the sensible choice for most visitors, since travel insurance generally excludes motorbike accidents without a licence valid for that engine size.
Departures Diary Editorial
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