Bhutan's climate is quite unpredictable and varies dramatically, with tropical climate in the south, temperate at the middle and cold to the north of the country. Like most of the Asian continent countries, Bhutan's climate is also largely affected by monsoon. The north-eastern monsoon brings powerful winds that pass through high mountain passes. A strange sound emerges from this natural phenomenon, lending Bhutan its nickname 'Land of the Thunder Dragon'.
The southern part of Bhutan is tropical, and in general, the east of Bhutan is warmer than the west of the country. The central valley of Punakha, Wangdiphodrang, Mongar, Tashigang and Lhuntshi enjoy a semi tropical climate with very cool winters, while Thimphu, Tongsa and Bumthang have a much harsher climate, with heavy monsoon rains in the summer and heavy snow fall in winter. Winter in Bhutan starts from mid-November till the mid-March, and at this time of the year the climate is dry with daytime temperature of 16-18° C and nighttime temperature falling below zero. The monsoon usually arrives in mid-June, with the rain falling mainly in the afternoons and evenings. Autumn starts from the end of September, after the last of the big rains, and it is a magnificent season for trekking-lasting till mid-November.
Average temperatures are as follows:
Place Jan/Feb Mar/Apr May/June July/Aug Sept / Oct Nov / Dec
Paro +13° +3° +15° +3° +23°+13° +25°+15° +22°+10° +12°+3° Thimphu +14° 0° +16° + 6° +22°+14° +27°+17° +20°+13° +16°+1° Punakha +18° +7° +24° +9° +22°+10° +26°+13° +25°+11° +22°+9° Wangdi +17° +7° +24°+11° +28°+18° +29°+20° +26°+17° +22°+7° Trongsa +12° +1° +16° +2° +20°+14° +18°+14° +17°+13° +16°+9° Bumthang +10° +1° +16° +5° +18°+10° +21°+13° +19°+11° +15°+2° Mongar +23°+10° +27°+11° +30°+20° +35°+22° +30°+18° +25°+8° Trashigang +16° +4° +19° +7° +20°+13° +22°+14° +20°+11° +16°+9°
The temperatures listed here are all in centigrade with the maximum temperatures on the left and the minimum temperatures on the right.
Climate is dry during winter months, which fall from December through February. However, total annual rainfall is around 650 millimeters. Rainfall commences from month and gradually increases, reaching to 220 millimeters in August.
BEST SEASON FOR BHUTAN TOURS
March to May and September to November are the best season months to visit Bhutan. Bring cotton or light woolen wear in summer (max temperature 30 degree C) and heavy woolens and jacket in winter (min temperature 1.1 degree C).