Nepal has cool, clear winters, pleasant moist springs, hot wet summers and fantastic mostly clear autumns. Traveling to Nepal is possible any time of the year. But it all depends on where you travel. Trekking is possible at anytime of the year depending on where you are going. The most popular seasons are autumn (September-December) and spring (February-May). Winter is very cold above 4000m. And high mountain passes may be snowbound, but it is good for trekking at lower altitudes. During the monsoon season (June-August), you can trek in the rain-shadow areas north of the Himalayan like Mustang, upper Manang and Dolpo. These places are out of reach of the rain clouds because of the high mountains and are unaffected by the monsoon. During the monsoon in Nepal it is recommended to travel in Tibet (May to September)
The rhododendron spring – March-April-May
Spring dances ever higher, painting the rhododendron hillsides. The arriving warmth generates staggering cloud formations and the occasional pre-monsoon downpour (everyone dives into the nearest house to wait the squalls out over tea). Some days are staggeringly fine, others the views cloud in around lunchtime or in the afternoon, great for reading and relaxing and just when you begin to worry about tomorrow, mostly the evenings turn sparklingly clear. This is the second traditional trekking season, and definitely less crowded but still a great time to trek.
March and April are often drier than May, but May has the advantage of more alpine flowers.
The monsoon (summer) June-July-August-September
In late May and early June at low altitude the heat stifles. Clouds billow ever higher cumulating in crescendos of rain. The downpours are usually brief leaving plenty of time to admire more than just the forces of nature. Katmandu is sticky, with rain as a relief and, in the Terai, elephants rather than jeeps are used for crossing the swollen rivers. The jungle is lush, vibrant and tropical. In the high rain-shadow areas it is surprisingly pleasant, balmy with only occasional showers. It is a time for wandering among the flower carpets and vivid colors while the locals are absorbed in the traditional cycles of agriculture. For this time of year I offer the trek to Rain shadow area in Manang and Mustang or Naar- Phu the hidden tradition in Manang.
The harvest – mid-September to mid-October
The monsoon dwindles in late September but a few tail-end clouds and showers (or short-lived snow at altitude) must be expected. Locals and trekkers simply take cover in the nearest teahouse and wait the afternoon shower out. There’s also a chance that the monsoon may not quite have ended, staging a dramatic return for a few weeks. The middle hills are either hot and sweaty under the fierce sun or perpetually grey and cloudy, while higher up it’s pleasant with cool but mostly frost-free nights. If you skip the lower country, this is a particularly pleasant and under-trekked season. At this time the whole country changes from a lush, verdant green into the harvest colors.
The perfect autumn – mid-October thru early December
This is classic trekking time, famed for clear skies and fantastic fine weather. Early October through to late November is also the busiest period with the teahouse regions brimming with trekkers. This is the season to head off the beaten track, to Kanchenjunga, Manaslu, Around Dhaulagiri as well.
The long fine periods are occasionally broken for day or two by a front sweeping overhead causing high cloud or cloud banks that roll up the valleys, and then usually clear at altitude with the sunset. The odd stronger front brings a spot of wet weather as well but it is impossible to tell (even the locals can’t) whether a front contains rain. Barring unusual conditions during this trekking season perhaps two or three periods of showers and drizzle, or short-lived snow at altitude, can be expected. In an odd year there is perpetual high cloud and less than crystal clear skies.
In the low country evenings are balmy while in the middle hills they are pleasantly chilly. Above the tree line (4000m) nights are sharp and below freezing, early morning sun is particularly welcome.
The Christmas’s winter
While trekking although winter, the weather is at its finest and driest; great conditions. It is the nights that are cold. In the middle hills nights are a crisp cool and clear, the high country the air is tinkling sharp and the stars have that crystal twinkle. Temperatures drop below freezing every night. Higher up after a snowfall only the Solu-Khumbu (Mt Everest region) Annapurna Sanctuary, Jomsom, Gosainkunda Helambu are reliably accessible and pleasant. Mostly fine, any light snow clears quickly while the deeper powder, yak-tracked, rarely slows us.