Best Time to Visit Thailand: Month by Month Guide [2026]
Cool season, hot season, monsoon season: when to go for beaches, temples, diving, and festivals
Where
The best time to visit Thailand is November through February, when temperatures drop to a comfortable 25-32°C (77-90°F), humidity eases, and rainfall is minimal across most of the country. This cool, dry season lines up with peak tourist demand, so expect higher hotel rates and crowded islands. But for reliable sunshine and pleasant conditions from Bangkok to Chiang Mai to Phuket, these four months are hard to beat.
Thailand spans roughly 1,600 km from north to south, and its climate varies significantly by region. The Gulf coast (Koh Samui, Koh Phangan, Koh Tao) runs on a different monsoon cycle than the Andaman coast (Phuket, Krabi, Koh Lanta). Understanding these regional differences is the key to timing your trip right, especially if you plan to island-hop or combine city sightseeing with beach time.
Thailand's Three Seasons Explained
Thailand has three distinct seasons rather than the four seasons familiar to travelers from temperate climates. Each one dramatically changes the travel experience.
Cool Season (November to February) is the most popular travel window. Temperatures in Bangkok average 26-31°C (79-88°F), while Chiang Mai dips to 15-28°C (59-82°F), cool enough for a light jacket at night. Rainfall drops to 20-50mm per month across most regions. This is peak season for northern trekking, temple tours, and Andaman coast beaches.
Hot Season (March to May) pushes temperatures to 35-40°C (95-104°F) in Bangkok and the central plains. April is typically the hottest month. Humidity climbs, and haze from agricultural burning can reduce air quality in the north during March. This is the low point for tourism in most areas, but Songkran (Thai New Year) in mid-April transforms the country into a massive water fight celebration.
Rainy Season (June to October) brings the southwest monsoon. Rain typically falls in intense afternoon bursts lasting 1-2 hours rather than all-day drizzle. September and October are the wettest months, with Bangkok receiving 300-350mm of rain. Hotel prices drop 30-50% from peak season, and popular sites like Wat Arun and the Grand Palace are far less crowded. Some Andaman islands close resorts and cancel ferry services, but the Gulf islands remain accessible.
Regional Climate Differences
Thailand is not one climate zone. The timing that works for Bangkok may not work for Koh Samui, and Chiang Mai has a completely different feel from Phuket. Here is what to expect in each major region.
Bangkok and Central Thailand
Bangkok is hot year-round, but the cool season (November to February) brings the most tolerable conditions at 26-31°C. The city floods occasionally during heavy monsoon rains in September and October. December and January are the best months for sightseeing, street food tours, and exploring temples without excessive sweat. Ayutthaya and Kanchanaburi follow the same pattern.
Chiang Mai and Northern Thailand
The north has the widest temperature range in Thailand. Chiang Mai sees lows of 14-15°C (57-59°F) in December and January, making it genuinely cool at night. The mountains around Chiang Rai and Pai can drop below 10°C. November through February is ideal for trekking, visiting hill tribe villages, and exploring night markets in comfort. March brings the burning season, when farmers clear fields and air quality deteriorates significantly. The Air Quality Index in Chiang Mai regularly exceeds 200 ("very unhealthy") during March and early April.
Phuket, Krabi, and the Andaman Coast
The Andaman coast runs on the southwest monsoon. Peak season is November through April, with the driest and calmest seas from December to March. May through October brings heavier surf, and some smaller islands like the Similan Islands close entirely from mid-May to mid-October. Phuket stays open year-round, but beach conditions and diving visibility are best from November to April. Expect 5-star resort prices to peak during Christmas and New Year, with rooms at places like Amanpuri or Trisara exceeding $1,500 per night.
Koh Samui, Koh Phangan, and the Gulf Coast
This is the critical exception. Koh Samui and the Gulf islands have an opposite monsoon pattern to the Andaman coast. The Gulf's wettest months are October and November, when the northeast monsoon dumps 400-500mm of rain. The best weather on Koh Samui, Koh Phangan, and Koh Tao is February through June, when seas are calm, visibility peaks for diving, and the Andaman side is entering its wet season. This makes the Gulf coast an excellent shoulder-season alternative when Phuket gets rain.
Month-by-Month Breakdown
January: Peak cool season. Bangkok 26°C, Chiang Mai 15-28°C. Driest month across most regions. Highest hotel prices. Chinese New Year falls in late January or February, bringing festive energy to Bangkok's Yaowarat (Chinatown) district.
February: Still cool season. Temperatures begin climbing slightly. Excellent for Andaman diving (Similan Islands at peak visibility, 25-30m). Koh Samui enters its best stretch. Makha Bucha (Buddhist holiday) brings candlelit temple processions.
March: Transition to hot season. Bangkok hits 34°C regularly. Northern Thailand burning season begins. Air quality in Chiang Mai deteriorates. Still good for southern beaches. Prices start dropping from peak.
April: Hottest month. Bangkok averages 35-36°C with spikes to 40°C. Songkran (April 13-15) is Thailand's biggest festival, a three-day water fight covering the entire country. Silom Road and Khao San Road in Bangkok are ground zero for the celebrations. Hotels in party areas book weeks in advance.
May: Monsoon arrives. Early rains cool temperatures slightly. Similan Islands close. Gulf islands (Koh Samui, Koh Tao) remain calm and sunny. Prices drop 30-40% at Andaman resorts. The Royal Plowing Ceremony marks the start of rice planting season.
June: Full monsoon on the Andaman side. Afternoon storms in Bangkok. Gulf coast still dry and great for diving. Whale sharks appear near Koh Tao from June through September. Low-season deals on flights from the US and Europe.
July: Moderate rainfall. Many travelers avoid Thailand, so prices remain low. Asanha Bucha and Khao Phansa (Buddhist Lent) bring temple ceremonies. Gulf islands remain the best beach option.
August: Rains intensify. Bangkok gets 200mm+. The Andaman coast is rough, but Koh Samui stays relatively dry with under 100mm. Budget hotels in Phuket drop to $30-50 per night. Queen's Birthday (Mother's Day) is August 12.
September: Wettest month for Bangkok and the north (300-350mm). Flooding risk in low-lying areas. Cheapest time to fly to Thailand from most origins. The Vegetarian Festival on Phuket (late September or October) is a dramatic spectacle with fire-walking and street processions.
October: End of monsoon for the Andaman coast. Gulf coast enters its wettest period (400-500mm on Koh Samui). Ok Phansa marks the end of Buddhist Lent with longboat races. Rains begin tapering in Bangkok.
November: Cool season returns. Loy Krathong (Festival of Lights) falls on the full moon in November, when thousands of floating lanterns and flower baskets fill rivers and canals across Thailand. Chiang Mai's Yi Peng lantern festival, held simultaneously, is one of the most photogenic events in Southeast Asia. Andaman coast reopens fully.
December: Peak season in full swing. Coolest month in the north. Best all-around weather for the entire country except the Gulf coast. Christmas and New Year push prices to annual highs, especially on Phuket and in luxury Bangkok hotels. Book at least 8 weeks ahead for holiday travel.
Festivals and Events Worth Planning Around
Thai festivals can define a trip. Songkran (April 13-15) turns every street into a water battle and is the single most fun public celebration in Southeast Asia, though the heat is brutal. Loy Krathong and Yi Peng in November combine riverside candle-floating with sky lantern releases in Chiang Mai, creating surreal nighttime visuals. Chinese New Year (January or February) lights up Bangkok's Yaowarat Road with dragon dances, food stalls, and red lanterns.
Koh Phangan's Full Moon Party runs monthly year-round, but the biggest events are December through March when 15,000-30,000 people pack Haad Rin beach. Half Moon and Black Moon parties on the same island offer smaller alternatives. The Phuket Vegetarian Festival (late September or October) features extreme rituals, street processions, and some of the best vegetarian street food in the country.
Diving Seasons by Region
Thailand is one of the cheapest places in the world to get PADI certified, with Open Water courses running $250-350 on Koh Tao. Timing your dive trip matters because visibility and marine life shift with the monsoons.
The Similan Islands (Andaman Sea) offer Thailand's best diving from November to April, with visibility reaching 25-30 meters and regular manta ray sightings. The site closes entirely from mid-May to mid-October. Koh Tao in the Gulf is diveable year-round, with the best visibility from April to September and whale shark season from June to September. Koh Lipe and the southern Andaman islands are best from November to April.
Budget Considerations: When Is Thailand Cheapest?
The cheapest time to visit Thailand is May through October, excluding Songkran week. During low season, budget guesthouses on Phuket drop to $20-40 per night compared with $60-120 in peak season. Flights from the US West Coast to Bangkok (BKK) average $550-700 round-trip in June versus $900-1,200 in December. Domestic flights on Thai AirAsia and Nok Air run 30-50% cheaper during monsoon months.
Shoulder season (March and November) offers a good balance. You get lower prices than peak season with better weather than the monsoon core. November is especially attractive because the rains are ending, Loy Krathong falls in this month, and hotel prices have not yet hit December highs.
A daily backpacker budget in Thailand runs about $30-50 per day covering hostel dorms, street food, and local transport. Mid-range travelers spending $80-150 per day can enjoy private air-conditioned rooms, sit-down restaurants, and organized tours. Luxury resorts on the islands start at $200-400 per night in low season and $500-1,500+ in peak.
Planning Tips for 2026
Book Andaman coast hotels (Phuket, Krabi, Koh Lanta) at least 6-8 weeks ahead for December through February stays. Songkran in April sells out accommodation in Bangkok, Chiang Mai, and Phuket rapidly, so reserve 4-6 weeks early. Gulf coast islands are more relaxed with booking lead times except during Full Moon Party weekends on Koh Phangan.
For the best all-around trip combining Bangkok, the north, and southern beaches, target late November or early December. You catch the start of cool season, Loy Krathong if the timing works, good Andaman conditions, and prices that have not yet hit Christmas peaks. If budget is your priority and you can handle afternoon rain, June and July on the Gulf coast deliver warm seas, whale sharks, cheap flights, and far fewer tourists at every temple and beach.
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Frequently Asked Questions
Common questions answered clearly and concisely
December is the best single month for most travelers. It falls in the middle of the cool, dry season with temperatures of 26-31°C in Bangkok and 15-28°C in Chiang Mai. Rainfall is minimal, the Andaman coast has calm seas, and Similan Islands diving is at peak visibility. The only downside is peak-season pricing, especially around Christmas and New Year.
Yes. Rain typically falls in short afternoon bursts of 1-2 hours, not all day. Prices drop 30-50%, tourist crowds thin out dramatically, and landscapes are green and lush. The Gulf islands (Koh Samui, Koh Tao) stay relatively dry from June to September while the Andaman side gets rain. Whale shark season on Koh Tao peaks during monsoon months.
June through September offers the lowest airfares. Round-trip flights from the US to Bangkok average $550-750 during these months versus $900-1,300 in December. Booking 6-8 weeks ahead and flying midweek (Tuesday or Wednesday) saves an additional 10-20%. May and October are also affordable with slightly better weather.
February through June is the best window for Koh Samui. The Gulf island has an opposite monsoon pattern to Phuket, so it stays dry and sunny while the Andaman coast gets rain. October and November are Koh Samui's wettest months with 400-500mm of rainfall. December through January is busy and pricey but offers good weather.
Avoid Chiang Mai in March and early April during the burning season. Farmers clear agricultural land by burning, and the AQI regularly exceeds 200 ("very unhealthy"), sometimes surpassing 300. Visibility drops, outdoor activities become unpleasant, and it poses health risks for people with respiratory conditions. The burning season typically eases by mid-April after the first monsoon rains.
Songkran runs April 13-15 and is Thailand's biggest celebration. The entire country participates in water fights, with Bangkok's Silom Road and Khao San Road as the main battlegrounds. It is worth planning for if you enjoy festivals and do not mind extreme heat (35-40°C). Book accommodation 4-6 weeks ahead. If you prefer a quieter trip, avoid this week entirely.
The Similan Islands and Andaman coast are best from November to April with 25-30m visibility and manta ray sightings. Koh Tao in the Gulf offers the best diving from April to September, with whale sharks appearing June through September. Koh Tao is diveable year-round and is the cheapest place in the world for PADI certification at $250-350.
No. Monsoon rain in Thailand typically falls in intense bursts lasting 1-2 hours, usually in the afternoon or evening. Mornings are often sunny. You can still enjoy beaches, temples, and sightseeing most of the day. September is the wettest month for Bangkok and the north, while October-November is wettest for the Gulf coast.
Loy Krathong falls on the full moon of November. The most spectacular celebration is in Chiang Mai, where the simultaneous Yi Peng festival releases thousands of sky lanterns alongside the traditional floating offerings on rivers. Sukhothai Historical Park hosts the most traditional version. Bangkok's Chao Phraya riverfront and Asiatique are also popular viewing spots.
Yes, but timing matters. The best overlap is late November through January, when both coasts have decent weather. From February through April, both are good. From May through September, stick to the Gulf side (Koh Samui, Koh Tao) because the Andaman coast is in full monsoon. Domestic flights between Phuket (HKT) and Koh Samui (USM) take about 1 hour and cost $50-120 on Bangkok Airways.