v256.0 · climate · TH · verified 2026-04
Thailand climate profile
Climate profile for Thailand — Köppen climate zones, seasonal temperature + rainfall, humidity, extreme weather, climate-change trajectory, air quality, best months for visiting + relocation, water security, and recent climate-policy changes.
Climate classification (Köppen)
Tropical monsoon (Am, Aw) most of country · Tropical savanna (Aw) interior · Year-round hot, two distinct wet/dry seasons
Temperature + rainfall by season
| Winter temperatures | Bangkok: 27°C avg (21-32°C, "cool" Dec-Feb) · Chiang Mai: 22°C (15-29°C, can drop to 10°C) · Phuket: 28°C (24-32°C) · Pattaya: 27°C (23-32°C) |
| Summer temperatures | Bangkok: 30°C avg (26-35°C, peaks 40°C+) · Chiang Mai: 29°C (24-36°C, hot season Mar-May, smoke season) · Phuket: 28°C (25-32°C, monsoon May-Oct) · Year-round hot |
| Annual rainfall | Bangkok: 1,650 mm · Chiang Mai: 1,150 mm · Phuket: 2,400 mm · Pattaya: 1,400 mm · Vast majority May-Oct (SW monsoon) · Nov-Apr dry |
| Humidity | 70-90% year-round · Coastal areas highest · Bangkok smoggy + humid · Chiang Mai dry season (Nov-Feb) more comfortable |
Climate zones within the country
Bangkok + central — tropical savanna · Chiang Mai + north — cooler in winter, hot Mar-May, burning-season smoke · Phuket + south — tropical rainforest, two monsoons · Andaman vs Gulf coast — opposite peak seasons
Extreme weather + risks
| Extreme weather events | Tropical storms + monsoon flooding May-Oct (Bangkok 2011 floods catastrophic) · Tsunami risk Andaman coast (2004 Indian Ocean) · Earthquakes rare · Flash flooding Bangkok recurrent |
| Air quality | POOR seasonal — Bangkok + Chiang Mai PM2.5 100-300+ µg/m³ Jan-Apr (burning season) · Outside burning season 30-60 µg/m³ · Monsoon cleanest air · Mask + air-purifier recommended Jan-Apr |
| Water security | Adequate but stressed seasonally · 2014-15 + 2019-20 drought severe · Climate-Change-driven monsoon-variability increasing |
Climate change trajectory
Annual mean +1.3°C since 1981 · Projected +2-4°C by 2100 · Sea-level rise threatens Bangkok (sinking + coastal erosion) · Bangkok 1m above sea-level vulnerable · Heat-wave frequency increasing
Best months for visiting + relocation
| Best for visiting | Nov-Feb — cool, dry, comfortable (especially Chiang Mai) · Mar-May hot + smoky · Jun-Oct monsoon (warm rain, lush, fewer crowds, lower prices) |
| Best for relocation | Nov-Feb arrival ideal (avoid burning season Mar-May + monsoon) |
Recent changes (2023-2026)
2024-25: Burning-season air quality regulations strengthening · Bangkok flood-mitigation investments continuing · Worldwide income taxation since Jan 2024 (180+ day residents) · Climate-vulnerable infrastructure adaptation planning
Source: official Thailand meteorological agency · Last verified 2026-04
See also: Thailand country profile · climate atlas