|Month||Values in Celsius||Paro||Thimphu||Punakha||Trongsa||Bumthang||Mongar||Trashigang|
The climate in Bhutan is extremely varied. This variation in the climatic conditions and average temperature can be attributed to two main factors, the vast differences in altitude present in the country and the influence of the north Indian monsoons. Southern Bhutan has a hot, humid sub-tropical climate that is fairly unchanging throughout the year. Temperatures can vary between 15-30 degrees Celsius. In the Central parts of the country the climate cools a bit, changing to temperate and deciduous forests with warm summers and cool, dry winters. In the far Northern reaches of the kingdom the weather is cold during winter. Mountain peaks are perpetually covered in snow and lower parts are still cool in summer owing to the high altitude terrain.
The Indian summer monsoon lasts from late-June through late-September and is mostly confined to the southern border region of Bhutan. It brings heavy rain and high humidity, to the southern region. These rains bring between 60 and 90 percent of the western region's rainfall.
Annual precipitation ranges widely in various parts of the country. In the northern border region to Tibet gets about forty millimeters of precipitation a year which is primarily snow. In the temperate central regions, a yearly average of around 1,000 millimeters is more common, and 7,800 millimeters per year has been registered at some locations in the humid, subtropical south, ensuring the thick tropical forest, or savanna.
Thimphu experiences dry winter months (December through February) and almost no precipitation until March, when rainfall averages 20 millimeters a month and increases steadily thereafter to a high of 220 millimeters in August for a total annual rainfall of nearly 650 millimeters.
Bhutan's generally dry spring starts in early March and lasts until mid-April. Summer weather commences in mid-April with occasional showers and continues to late June. The heavier summer rains last from late June through late September which is more monsoonal along the southwest border.
Autumn, from late September or early October to late November, follows the rainy season. It is characterized by bright, sunny days and some early snowfalls 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 at the highest altitudes through high mountain passes, giving Bhutan its name - Drukyul, which in the Dzongkha language mean Land of the Thunder Dragon.
Bhutan has a season for everyone. The kingdom stretches across three climatic zones - from the sub-tropical jungles in the south, to the moderate heights of 2000-2500 meters in the centre and up to the alpine world of the towering Himalayas. Temperatures in the central valleys do not normally exceed 30°c in the summer and in the winter around 15°c during the day.
Spring is a botanist’s delight as rhododendrons, wild azaleas, and masses of wild flowers including the edelweiss cover the meadows like carpet. Pear and apple blossoms add a dainty touch to the valleys as their pink and white blooms add a sense of new wonder to the land.
Summer is an abundant time of the year as flowers are in bloom and valleys are covered in green, weeping willows sweep the banks of many of the rivers and the pine cone glisten in the sun, so full with resin they are ready to plummet to the ground.
Autumn casts a bright golden glow on the vast landscape. The rice fields ripen to a golden brown under crisp blue skies. The merry pink and white of cosmos flowers dot the countryside.
Winter has its moments. The days are full of sunshine while evenings can turn chilly. Soft turfs of clouds drape lazily over mountain tops as if waiting for new life to blow it across the landscape