Bhutan enjoys four seasons each having its advantages and disadvantages to the visitor. The southern plains close to the Indian border are warmer and more tropical than higher central valleys. Spring is perhaps the most beautiful time of the year when the fierce cold that characterizes the winter months tends to subside towards the end of February with beautiful Rhododendron blooming with spectacular flaming red, pink and white colors. Summer months in the southern region are generally hot whereas in other parts of the country it is warm and pleasant with average maximum temperatures not exceeding 30 degrees Celsius and the minimum at around 10-15 degrees Celsius. The annual monsoon from the Bay of Bengal is also experienced around the country between June and September.
The autumn months from September to November bring shorter days and cooler evenings. The days are crisp with clear skies. Views over the Himalayas are usually the best during September to March. Beginning December the weather takes on its winter coat where days remain crisp and the nights turn cold. The southern region however being much lower have a more temperate climate and considerably warmer winters.
- Nepal Tibet Tours & Treks