Koh Samui is situated in the Gulf of
Siam and its annual weather cycle is ruled by two opposing
wind systems, namely the Northeast Monsoon, and the
Southwest Monsoon. Visitors to Samui who follow the
general guidebooks (which as far as the description
of Samui's weather pattern is concerned are usually
wrong) are often taken by surprise by the weather here
upon their arrival. The weather patterns on the southeast
coast of Thailand (and therefore Koh Samui) are the
opposite of those elsewhere in the country:
WET/ COOL: Mid October through mid March,
when the north-easterlies blow, is considered the rainy
season on Koh Samui. However, the peak of stormy and
rainy weather is usually at the onset of the season,
and by mid December the weather generally clears up
with extended periods of dry and often sunny weather
from Christmas onwards. The rainy season is also our
cool season, with temperatures ranging between a very
pleasant 25 and 30°C.
DRY/ HOT: By March the north-easterlies
are dying down, and the weather starts warming up. Wind-free
days are more the rule than the exception, and as the
sun on its path north passes through its zenith during
this time of the year, the days become hot and dry.
Daytime temperatures during April and May can rise to
DRY/ WARM: Once the south-west monsoon
sets in in June the temperatures drop again to a comfortable
30°C or slightly above. While the rest of the country
suffers through its hot season, Koh Samui, due to its
unique geographic position, is only marginally affected.
Indeed the island experiences some of its finest weather
during this period. A steady westerly breeze and a lot
of sunshine should be the rule, only occasionally upset
by thunderstorms or strong winds with rain.
Of course, the above are general guidelines
based on a climatic pattern which has prevailed and
ruled the lives of Southeast Asia's communities over
thousands of years. Of course there are always exceptions
to these general patterns. It might storm in the so-called
dry season, or we could have months of dry weather during
the 'rainy' season.
hot is hot?
The average annual temperature in Samui is around
a comfortable 30 degrees centigrade in the daytime,
and hardly fluctuates from season to season. During
the rainy (low) season, it cools down to about 28 degrees
during the day and is much cooler at night. For a short
time in April and May we might even see 34 degrees.
We have built all our houses using largely natural
materials, with lots of wood, and taken advantage of
the prevailing winds so that air-conditioning is not
necessary. All the houses have effective ceiling fans.