Bhutan
is a mountainous country with some fertile valleys and savanna. Its climate
varies greatly: tropical in the southern plains; cold winters and hot
summers in central valleys; and severe winters and cool summers in the
Himalayas with year-round snow on the main summits. As in most of Asia, the,
monsoons dominate the weather patterns, and the altitude and elevation also
has a huge impact; hence conditions can vary dramatically from place to
place; and day to day.
The three relief zones (the foothills, the
Central Himalayan valleys and the High Himalayas) also define three climatic
regions: tropical, temperate with monsoon and alpine with monsoon. The
southern part of Bhutan is tropical, and in general the east of Bhutan is
warmer than the west of the country. Western Bhutan is particularly affected
by the monsoons that bring between 60 and 90 percent of the region's
rainfall. Mid December to early January can be beautifully clear and dry
here. Fluctuations are not so dramatic in summer and daytime temperatures
often rise to 30° Centigrade.
In the Thimphu and Paro
valleys, daytime temperature in winter averages 20° Centigrade during
clear winter days but drops well below freezing during the night with light
snowfall and occasional snowstorms. The Punakha and the central valleys tend
to be warmer and enjoy a semi tropical climate with very cool winters. The
high mountain peaks are snow covered through the year and the mountain
passes, especially Thrumsing La (between Bumthang and Mongar), can be
treacherous during winter. Bhutan's generally dry spring starts in early
March and lasts until mid-April. With splashes of colour everywhere it is
supremely multihued and can only be compared to an artist's palette. Summer
weather commences in mid-April with occasional showers and continues through
the premonsoon rains of late June. The summer monsoon lasts from late June
through late September with heavy rains from the southwest. The monsoon
weather, its northward progress blocked by the Himalayas, brings heavy
rains, high humidity, flash floods and landslides, and numerous misty,
overcast days. The views of the Himalayas are completely obscured by clouds
and rain from May to August while spectacular rhododendrons bloom in the
verdant valleys in this season. Autumn, from late September or early October
to late November, follows the rainy season. It is characterized by bright,
sunny days and some early snowfall at higher elevations. From late November
until March, winter sets in, with frost throughout much of the country and
snowfall common above elevations of 3,000 meters. The winter northeast
monsoon brings gale-force winds down through High Mountain passes, giving
Bhutan its name - Drukyul, which in the Dzongkha language means Land of the
Thunder Dragon.
