Climate and monthly weather forecast
Ko Lanta, Thailand

Situated in Thailand's southern region, the island of Ko Lanta enjoys a Tropical Monsoon climate, classified as "Am" based on the famous Köppen climate classification. This type of climate is characterized by high temperatures and heavy rainfall, especially during the monsoon season.

Throughout the year, monthly average temperatures in Ko Lanta consistently remain above 23°C (73.4°F), potentially reaching a peak of 34.1°C (93.4°F). The least variation is observed in the low-temperature averages, which settle from 23.6°C (74.5°F) to 25.4°C (77.7°F). In terms of relative humidity, the annual pattern shows a minor fluctuation between 74% and 85%, indicating a predominantly moist atmosphere.

Rainfall patterns in Ko Lanta prominently illustrate a monsoonal climate. The driest months lie between January and March with rainfall going from 15mm (0.59") to 60mm (2.36"). A sharp rise is seen in April, peaking from September to October with values surpassing 300mm (11.81"). Correspondingly, the number of rainfall days rises from 3 days in the early part of the year to 22 days in September.

The daylight hours in Ko Lanta display a narrow range throughout the year, fluctuating only from 11.7 to 12.6 hours.

Taking all weather conditions into account, it may be preferable to visit Ko Lanta from November to March. During this period, the island experiences less rainfall, with November and December observing the least with 56mm (2.2") and 15mm (0.59") respectively. The temperature during these months is pleasantly warm, remaining between 30.9°C (87.6°F) and 31.2°C (88.2°F) for the highs, and 24.1°C (75.4°F) to 23.6°C (74.5°F) for the lows, providing a conducive environment for outdoor activities and beachside recreation.

Those who prefer to avoid heavy rainfall and high humidity might find the period between May and October less suitable for a visit to Ko Lanta. This is the wettest period of the year, with rainfall exceeding 245mm (9.65"), peaking at 330mm (12.99") in September. The number of rainy days also drastically increase during this period, reaching 22 days in the monsoon peak of September. The highest recorded average temperature of 33.9°C (93°F) has been observed during these months, adding to the discomfort.

The spring season, observed from March to May, gradually ushers in the monsoon in Ko Lanta. The average maximum temperatures lie from 34.1°C (93.4°F) to 32.5°C (90.5°F), while the minimum temperatures slightly increase from 24.6°C (76.3°F) to 25.3°C (77.5°F). Rainfall starts to intensify, especially in May when it jumps to 245mm (9.65").

The summer season in Ko Lanta, lasting from June to August, is characterized by the peak monsoon. These months see the highest levels of rainfall, ranging from 259mm (10.2") to 304mm (11.97"), along with the highest average minimum temperatures of 25.4°C (77.7°F) in June. The number of rainfall days hits 18 during this period, contributing to the heightened humidity of 85%.

In autumn, from September to November, Ko Lanta experiences a gradually receding monsoon. While September still witnesses the year’s maximum rainfall of 330mm (12.99"), there is a steady decrease in rainfall going down to 147mm (5.79") by November.

During the winter months of December to February, Ko Lanta experiences the driest conditions. Rainfall drops drastically going from 15mm (0.59") in January up to 60mm (2.36") in February. Temperatures during these months provide a comforting warmth, with the maximum values stabilizing between 31°C (87.8°F) and 32.7°C (90.9°F), while the lows settling between 23.9°C (75°F) and 24.1°C (75.4°F). These conditions make winter a well-suited season for visiting Ko Lanta.

Ko Lanta, Thailand, opens its year with comfortingly warm temperatures and lower than average humidity. January is cooler when compared with the upcoming months, providing relief from the traditionally humid, tropical climate of the region. Weather in January »

The climate in February experiences a slight increase in temperature from January, making it noticeably warmer. Despite the rise in temperature, February weather maintains a comfortable atmosphere, suitable for beach activities. Weather in February »

March indicates an arrival of more prominent tropical weather characteristics. Heat levels rise moderately from February, while rainfall escalates considerably, signifying a transition towards Ko Lanta’s rainy season. Darker cloud cover becomes prevalent, the number of rainfall days increases to a monthly total of 3 days, and the downpours become more sustained. Weather in March »

April features some of the most balanced weather conditions in Ko Lanta, despite seeing an increase in rainfall from March. The temperature remains stable, only showing minor fluctuations compared to March. As the month unfolds, the thickening cloud cover hints at the impending onset of the monsoon season. Weather in April »

As May unfolds, the climate undergoes significant changes. The weather in this part of Ko Lanta becomes very humid, marking the proper commencement of the wet season. The temperature sees a moderate decrease from April, but it's the abundant rainfall that stands out in this month. Weather in May »

June sees continuity in the wet season, with substantial rainfall and high humidity characterising the weather in Ko Lanta. Although the temperature decreases slightly from May, the heavy cloud cover and abundant rain make this a less desirable time for outdoor activities. Weather in June »

July’s arrival brings small and steady changes to the climate. A minor dip in temperature joins the already established high rainfall and relative humidity pattern from June. Dense cloud cover becomes a common occurrence, and the gathering moisture brings about an atmospheric change. Weather in July »

The weather in August witnesses marginal changes from July. Ko Lanta experiences a slight decrease in temperature, while rainfall continues to rise. Though the heavy rains can be daunting for some, they do provide a significant relief from the region’s typical high temperatures. Weather in August »

September sees the peak of the rainy season in Ko Lanta. Rainfall reaches its annual maximum at 330mm (12.99") spread across 22 days. Subsequent flooding is common during this period, causing widespread saturation of soil and local water bodies. Weather in September »

October signals the withdrawal of the monsoon season in Ko Lanta. Decreased cloud coverage allows more sunlight to break through leading to a slight rise in temperature. Despite reduced rainfall, the effects of the previous heavy rains continue to be felt, with significant surface moisture present. Weather in October »

The last month of the autumn, November, is also a hot month in Ko Lanta, Thailand, with temperature in the range of an average high of 31°C (87.8°F) and an average low of 24.1°C (75.4°F). Ko Lanta's November showcases an average high-temperature of a still hot 31°C (87.8°F), hardly distinct from October's 30.9°C (87.6°F). Weather in November »

December marks the formal conclusion of the rainy season in Ko Lanta, a trend that began in November. The temperatures are comfortably warm, with considerably less rain and a decline in relative humidity, signalling the impending arrival of the dry season. Weather in December »