The altitude has a significant impact on the weather in Bhutan. The weather is arctic-like, cold, and frosty in the northern regions, where mountains can reach heights of 7,000 meters (22,966 feet). Due to the high-altitude geography, mountain summits are perpetually covered with snow, and lower areas are still chilly during the summer.
In the southern belts, the summers are hot and muggy, and the winters are cool. In these areas, temperatures can range from 15 to 30 °C (59 to 86 °F).
With temperate and deciduous forests, the country's central regions have a more seasonally variable climate with warm summers and mild, dry winters. Due to both variations in altitude and the effect of the north Indian monsoon, Bhutan's climate is generally very variable.
Bhutan has four distinct seasons: Winter, Summer, Fall (Autumn), and Spring.
Spring season (March-May): One of the ideal times to travel to Bhutan is probably during the spring season, which lasts from March through May. This time of year, the average daytime temperature is 17°C (63°F), while the typical overnight low is 7°C (45°F). The calm pathways of Bhutan's remote wilderness places are also fantastic for hiking in the spring. Spring offers a great view of the landscapes and the beauty of the nature of the nation.
Summer/Monsoon season (June – August): As the monsoon season begins throughout the summer months of June through August, nearly the entire nation receives rainy weather. This time of year, the average daytime temperature is 24 °C (75 °F), while the average overnight temperature is 14 °C (57 °F). Visiting Bhutan in the summer/monsoon is not a bad idea. you can get the perfect greenery view of the monsoon with the amazing rain drops and the washed view of the mountains as well.
Autumn or the fall season (October – December): Bhutan is best visited in the fall or autumn, between October and December, when the temperature is moderate and there may not be any flowers blooming in the valleys. During this season, the daily average high is 22 °C (71 °F), and the average low is 12 °C (54 °F). Up until mid-November, the weather is pleasant and the visibility of the mountains is very clear. It is one of the very pleasant times of the year to visit the Himalayan nation in the world.
Winter season (December – February): The coldest part of the year is generally the winter, which lasts from December through February. This season's typical daytime high is 10 °C (50 °F), while typical overnight lows are 0 °C (32 °F). The northeast monsoon's freezing winds add to the region's cold temperature. The coldest month of the year is January.