Bhutan experiences great variations in its climate. In general summers are warm with average daily temperature ranging from 20 to 25 degrees Celsius, while winter temperatures are usually below 15 degrees Celsius.
The northern regions of the country are colder than the more tropical south and it is recommended you pack accordingly. Trekkers will need to bring appropriate warm clothes and comfortable hiking boots (well broken in) preferably with ankle support and weather-proof to complement the weather and rugged terrain.
Others suggested items to pack:
• A pair of sunglasses
• Sunscreen lotion
• Spare camera batteries
• Flash light (with spare batteries)
• Travel sickness tablets
• Antiseptic cream
• Anti-histamine cream
• Anti-diarrhoea pills
• Altitude sickness medication it trekking above 3000m
• Insect repellent
– See more at: http://www.tourism.gov.bt/travel-tips/travelling-kits#sthash.Q8ZP4UzZ.dpuf