Climate and monthly weather forecast
Thailand

Thailand has a predominantly tropical wet and dry climate (Köppen climate classification Aw) in the north and tropical monsoon type of climate (Köppen Am) in the south. A few sections in the western and southern regions harbor tropical rainforests (Köppen Af). The extreme north has few regions with a temperate climate (Köppen Cwa, Cwb), with warm to hot summers and dry winters. Thailand lies in Southeast Asia, entirely between the equator and the Tropic of Cancer. Laos and Cambodia are in the east, Malaysia and the Gulf of Thailand in the south, Myanmar and the Andaman Sea in the west, and Laos and Myanmar in the north. The tropical location and monsoon rains, along with proximity to large water bodies, chiefly influence the climate.

Thailand has several geographical regions with varied topography. Northern Thailand is mountainous and a source of several important rivers. The northeast region is mainly a plateau that sits on a high-level plain. Doi Inthanon in Chiang Mai is the highest mountain in the north, at 2595 meters. The Yom, Nan, Ping, and Wang rivers unite to form the Chao Phraya River in the broad, low-level plain of the central region. The eastern portion mostly consists of plains and valleys and kisses the Gulf of Thailand in its south. Southern Thailand is a peninsula between the Andaman Sea in the west and the South China Sea in the east. The long ridge of western mountains extends from the north and central regions, all the way to the south. The Phuket and Nakhon Si Thammarat ridges separate the southern portion into western and eastern coasts. The Mekong and Chao Phraya are famous rivers. The Bang Pakong, Mae Klong, Tapi, and Chao Phraya rivers drain into the Gulf of Thailand, whose clear shallow waters along the southern region are famous for tourism. The islands along the Andaman Sea coast, such as Phuket, Phang Nga, Trang, and Krabi are tourist hotspots.

The best time to visit Thailand is post-monsoon, during the pleasant months from November to February. The skies are clear, and the temperatures are in the most comfortable range of the year. Cold and dry air masses from China keep northern Thailand in their grip. Bangkok and the western coast, including Phuket, Krabi, and the Phi Phi Islands have excellent weather until early summer. The east coast along the Gulf of Thailand is a great vacation destination until mid-summer. The greenery soothes the eyes after the rainy season. Budget travelers find the final phase of the wet season cheap on the wallet and the weather to be moderate.

The worst time to visit Thailand is during April and May when the summer is at its peak. Temperatures frequently cross 40°C (104°F) in the hinterland, and the conditions are dry. June provides relief in the form of the southwest monsoon, but the heat and humidity are often high. The heat index in Bangkok and many other cities is high due to the urban heat island effect. July and August bring heavy rainfall along the western coast of Thailand. The rain, heat, and humidity are occasionally unbearable for visitors from the temperate weather zones. Additionally, tropical cyclones are active in the rainy season, and it is prudent to skip the wet period for a vacation.

Thailand doesn't experience spring in the traditional sense. However, the period from late February to May can be compared to spring in many other regions. During this time, the country gradually warms up. Temperatures begin climbing, and the environment becomes drier. While March sees averages from 32.2°C (90°F) to 34°C (93.2°F), the heat intensifies by April. This phase is marked by limited rainfall, making it a time for various local festivals celebrating the approaching summer.

Thailand's summer spans from March to May. This season is characterized by strong heat, with temperatures ranging from 32.2°C (90°F) to 36.1°C (97°F), and occasional peaks beyond 40°C (104°F). Inland areas, especially in the north, experience relentless warmth. While peninsular regions near the Gulf of Thailand have slightly milder summers, the season is predominantly dry with sporadic showers.

Thailand lacks a conventional autumn. However, the transition from the rainy to the winter season, primarily from October to November, is somewhat reminiscent of autumn. During these months, the rain starts to recede, and the humidity levels drop. The temperature also begins to dip, setting the stage for the upcoming winter months. The vegetation remains lush from the monsoon, offering picturesque landscapes.

Winter in Thailand is from November to late February. During these months, the weather becomes more pleasant and cooler, especially in the northern regions near Myanmar and Laos. Bangkok and its vicinity maintain temperature averages from 31.1°C (88°F) to 32.2°C (90°F). While not cold in a traditional sense, the drop in temperatures from the preceding months makes this season a favored time for tourism and outdoor activities. Northern mountainous areas offer more temperate conditions, making them popular winter destinations.

January is nestled in the heart of Thailand's winter season, marking one of the most pleasant months in terms of weather. The entire country enjoys a reprieve from the intense heat and heavy rainfall experienced in the preceding months. Weather in January »

February continues to be a part of Thailand's winter season, and while it's still considered a cooler month, there's a notable transition as the country edges towards its summer. The average temperatures begin to show a slight uptick compared to January. In the northern regions close to Myanmar and Laos, temperatures remain cooler but start to warm up as the month progresses. Weather in February »

March heralds the commencement of summer in Thailand, marking a perceptible change in the weather landscape. The temperature across the country escalates, bringing warmer days and introducing a more pronounced heat in various regions. The northern areas, adjacent to Myanmar and Laos, although having a more temperate climate in the previous months, now experience a shift with temperatures climbing noticeably. Weather in March »

April stands out as the zenith of Thailand's summer, characterized by soaring temperatures and a palpable increase in heat intensity. This month consistently records some of the highest temperatures of the year, with certain areas frequently experiencing their hottest days during this period. In the northern regions, near Myanmar and Laos, the warmth is accentuated. Weather in April »

May acts as a transitional month in Thailand, bridging the gap between the intense summer and the onset of the monsoon season. As May progresses, there's an evident shift in weather dynamics with temperatures slightly receding, coupled with an increase in humidity and rain showers. Northern Thailand, near the borders with Myanmar and Laos, starts experiencing more cloud cover and occasional rain showers. Weather in May »

With June, Thailand finds itself firmly ensconced in the rainy season, a period defined by increased humidity, cloud cover, and frequent rainfall. The southwest monsoon's influence becomes more pronounced, bringing along with it a distinctive change in the weather scenario. The northern territories, neighboring Myanmar and Laos, exhibit a conspicuous uptick in rainfall. Weather in June »

July marks the continuation of Thailand's monsoon season, with many regions of the country experiencing regular, and sometimes heavy, rainfall. The pervasive southwest monsoon ensures that the weather remains moist, cloudy, and humid across the majority of the country. Northern Thailand, especially areas proximate to Myanmar and Laos, sees consistent rain showers. Weather in July »

August stands as one of the peak months for the monsoon season in Thailand. Rainfall reaches its zenith in many regions, and the cloud cover remains dense, casting a subdued light across the landscape. In Northern Thailand, regions adjacent to Myanmar and Laos, rainfall becomes a daily affair. Weather in August »

As Thailand enters September, the monsoon season shows initial signs of tapering off, especially towards the month's end. While rain remains frequent, the intensity and duration of downpours start to lessen in several regions, hinting at the upcoming transition to drier months. In Northern Thailand, adjoining Myanmar and Laos, the rain persists but becomes somewhat sporadic. Weather in September »

October in Thailand marks a pivotal turn in weather patterns. As the month unfolds, the monsoon season gradually draws to a close, ushering in the onset of cooler and more pleasant days, especially towards its conclusion. Northern Thailand, particularly regions bordering Myanmar and Laos, begins to experience a significant reduction in rainfall. Weather in October »

November in Thailand signals the definitive arrival of the dry season. Characterized by pleasant temperatures, reduced humidity, and minimal rainfall, this month ushers in one of the most favorable periods to experience the country's scenic beauty and diverse offerings. Northern Thailand, especially the areas adjoining Myanmar and Laos, becomes an epitome of tropical winter charm. Weather in November »

December is often celebrated as one of the most delightful months to explore Thailand. The culmination of the dry season's onset, this month offers consistently pleasant weather, making it particularly alluring for tourists and locals alike. In Northern Thailand, areas adjacent to Myanmar and Laos revel in their coolest phase. Weather in December »