Nepal experience 4 seasons – Spring ( March – May ), Summer ( June – August), Autumn (Sept. – Nov.) and Winter (Dec.-Feb.). The climate is varied ranging from the sub-tropical Terai to the cool dry temperate and alpine climates in the northern Himalayan ranges. The Terai is the hottest part of the country, summer temperature may rise as high as 40ºc and is hot and humid. In the mid mountain regions, the summer is mild with temperature around 25º-27ºc. The winter temperature range from 7ºc to 23ºc in the Terai and sub-zero to 12ºc in the mountain regions and valleys. The northern Himalayan region has a frigid climate. The valley of Kathmandu has a pleasant climate with an average summer temperature of 19º-27ºc and winter temperature of 2º-12ºc respectively.
Rainfall is extensive during the south-west monsoon period from June to August with the eastern part receiving the maximum rainfall. In the winter season, the western part receives a larger portion of rainfall. The period from October to May is generally dry in most parts of the country. Annual rainfall varies from around 300 mm. in the northern and western areas to over 2500 mm. in the eastern region. Kathmandu Valley receives around 1300 mm. of rainfall annually with a heavy congestion from June to August.
Nepal is located on the northern hemisphere therefore the seasons are similar to the ones in Europe. But since it is more to the South, it is naturally hotter in Nepal and the winters are colder in Europe. It seldom snows below 2000m. Trekking is possible all throughout the year in different regions of Nepal.
The period from March to May is that of forwarding in mountains. It is the best period to climb to the top of more than 5000m. We can have an excellent scene from the top.The temperature is completely acceptable even at night.
The period from June to August is the rainy season in Nepal but in Mustang, Dolpo, Rara and Simikot trekking is possible because these region are located on the lee-ward side of the Himalayan range and hence no rain falls in these areas including Tibet, which is the best region for tour and trekking in summer.
The period from Mid-September to Mid-December is best season for the treks. The weather is very fine and the sights on the top are very clear during this period.
The period from the Mid-December to Mid February is appropriate for the treks of low altitude.
Necessary for day: - affairs of toilet soap, towel, photo material, protection or sunglasses, water bottle, sunburn lotion, cream for lips, flashlight, umbrella, Kitbag, sleeping bag and necessary medicines, etc.