- ✓March opens Thailand's hot season — days climb into the mid-thirties in Bangkok and on the plains, so plan early-temple starts and a cooler, air-conditioned midday.
- ✓The beaches stay excellent: the Andaman is still in its dry Nov–Apr window and the Gulf islands are reliably calm and sunny, so March is one of the last big dry-island months before the green season.
- ✓The big watch-out is the North: the agricultural burning/smoke season is typically at or near its worst in March, with weeks of haze possible in Chiang Mai, Chiang Rai and Pai — check air quality before committing.
- ✓Crowds ease slightly from the January–February peak but prices stay high on the coasts; pool hotels and shaded itineraries pay off as the heat rises.
- ✓Best for beach and island travellers, divers, and anyone who'd rather swap the smoky North for the coast this month.
March weather, region by region
March is the hinge between the cool season and the hot one. Bangkok and the central plains start to warm up in earnest — daytime temperatures climb into the mid-thirties, humidity creeps up, and the comfortable cool-season mornings give way to genuinely hot afternoons. The trick for city sightseeing this month is the heat-smart day: temples and markets early, an air-conditioned or poolside midday, and the river or rooftops in the cooler evening.
The coasts, by contrast, are still in fine shape. The Andaman (Phuket, Krabi, Phi Phi, Lanta) remains within its November-to-April dry season, so beaches are sunny and seas are calm, and the Gulf islands (Samui, Phangan, Tao) are reliably dry and warm too. The sea breeze takes the edge off the rising heat, which is exactly why March is a popular month to be on an island rather than inland.
The North is the problem region in March. This is typically the worst stretch of the dry-season burning/smoke season, when agricultural and forest fires across the northern highlands can blanket Chiang Mai, Chiang Rai and Pai in haze for weeks, pushing air-quality readings to unhealthy levels and hiding the mountain views. It's not a hard rule — some years are milder — but March is the month travellers sensitive to smoke should most seriously consider rerouting away from the North, or at least checking live readings before they go.
The coast call — Andaman or Gulf in March
The Andaman is often more settled in March than during its mid-year monsoon period, while Gulf conditions vary by island. Heat rises and northern haze can be severe. Check live air quality, marine forecasts and operator schedules rather than treating either coast as guaranteed.
The Gulf islands are equally dependable this month — dry, warm and calm — and remain the better pick for Koh Tao diving, Koh Phangan and the family-friendly resorts of Koh Samui. With both coasts in good shape, base on whichever fits the holiday you're after, and note that the Gulf's own wet season is still a long way off (its heavy rain comes much later in the year).
Don't mix coasts on a short trip — crossing the peninsula between an Andaman and a Gulf island is a full travel day. Keep island-hopping within one coast. As the hot season builds, a hotel with a good pool and shade is worth prioritising, and as ever, confirm current sea and ferry conditions before locking a specific island and boat.
What to do — and what to avoid — in March
March is a beach-and-island month, and that's how to plan it. The coasts are still dry, so this is a strong window for island day trips, snorkelling, diving and simply slowing down at a pool-side resort. In the cities, lean into the heat-smart rhythm — early starts, midday in the shade or air conditioning, evenings out — and you'll enjoy Bangkok and the central plains comfortably enough. The heritage towns and parks are doable too, just plan around the midday heat.
What to avoid in March is the smoky North, at least if you're sensitive to air quality: this is the month the burning season most often bites, and a few unlucky days can mean grey skies, irritated eyes and hidden mountain views. If the North is a must, check live air-quality data and have a coast or central plan ready as a fallback. The other thing to watch is simply the heat — don't over-schedule outdoor sightseeing in the middle of the day. Crowds and prices ease a little from the January–February peak, but the coasts are still high-season, so keep booking beach hotels and internal flights ahead.
Sources and official planning resources
Thailand in March · at a glanceMonth FC
- Season
- Start of the hot season — rising heat on the plains; islands still dry
- Coast timing
- Andaman still in its dry window (Nov–Apr); Gulf calm & sunny — both coasts good
- Crowds & price
- Easing from the Jan–Feb peak but still high-season pricing on the coast
- Best for
- Beach and island travellers, divers, pool-hotel relaxers
- Verify event dates
- Northern smoke season is volatile year to year — check live air-quality readings
