Two good seasons and two hard ones
Nepal's trekking calendar is shaped by the South Asian monsoon. From about June to September, moist air from the Bay of Bengal brings heavy rain to the southern slopes of the Himalaya, including most of the Langtang and Manaslu regions. When the monsoon withdraws, usually in late September or early October, the air is washed clean and the skies stay clear for weeks. That is why autumn is the classic trekking season. Spring, from March to May, is the second season: warmer, with flowers in the forest, but hazier.
Winter and the monsoon are not off limits, but they change which treks make sense. In winter, high passes like the Larkya La and the Laurebina La are often under snow, while lower routes like Helambu are clear and quiet. In the monsoon, the roads to Syabrubesi and Machha Khola become the main risk, more than the trails themselves. The month-by-month table below shows how we rate each area.
Month by month at a glance
Ratings are ours, for walkers with a licensed guide and normal fitness. Good means a sound choice; best means the most reliable weather; poor means possible with care; avoid means we do not recommend it for most people.
| Month | Langtang Valley and Helambu | Gosaikunda | Manaslu Circuit and Tsum |
|---|---|---|---|
| January | Good for Helambu; cold at Kyanjin | Poor: snow and ice | Avoid: Larkya La usually snowbound |
| February | Good; cold nights, clear days | Poor to good, snow possible | Avoid for Manaslu; Tsum possible but cold |
| March | Best; rhododendrons begin | Best late in the month | Good for Tsum; snow likely on the pass |
| April | Best; flowers, warmer | Best | Best spring month for the circuit |
| May | Good; haze and afternoon showers | Good | Good, but hotter in the gorge and showers build |
| June | Avoid: monsoon begins | Avoid | Avoid: landslides in the gorge |
| July | Avoid | Festival only, if Janai Purnima falls | Avoid; upper Tsum drier but approach is wet |
| August | Avoid | Festival month for Janai Purnima | Avoid |
| September | Good late in the month | Good late in the month | Good from mid-month; trails still wet |
| October | Best | Best | Best |
| November | Best; colder nights | Best | Best; pass colder, icy late in month |
| December | Good; cold and clear | Good early, snow possible later | Possible with care; storms can close the pass |
Autumn: September to November
Autumn is the season most people want, and for good reason. By October the rain has gone, the rivers run clear, terraces are golden with rice and millet, and the peaks stand sharp against blue skies from early morning to mid-afternoon. At Kyanjin Gompa, days in the sun are around 10 to 15 °C and nights drop below freezing; at Samdo and Dharamsala nights are colder still. The Larkya La is usually free of deep snow from early October to mid-November.
Autumn is also festival season. Dashain and Tihar, Nepal's two biggest festivals, usually fall in October or early November. Buses and roads are packed as people go home, and government offices close for several days, which affects restricted area permits for Manaslu and Tsum. Late September can still bring heavy rain and landslides on the roads, so we prefer departures from about the first week of October. Book lodges at Dharamsala and Samagaon early for late October.
A planner can turn what you are reading into days, nights and a price.
Winter: December to February
Winter brings the clearest air of the year and the fewest trekkers. In the Kathmandu valley and on the Helambu ridges days are crisp and sunny, and nights at Chisapani or Tharepati fall well below freezing. The Langtang Valley stays open, but Kyanjin Gompa is bitterly cold at night and some lodges close. Gosaikunda freezes solid, and snow can block the trail from Sing Gompa upward for days after storms.
For Manaslu, winter is the hardest season. Snow often closes the Larkya La from December to February, and many lodges in Samdo and Dharamsala shut. If you must trek then, choose the Tsum Valley or the lower Manaslu villages and return the way you came, or plan the circuit with spare days and accept you may have to turn back. Warm kit is essential: a down jacket and a sleeping bag rated to about −15 °C.
Spring: March to May
Spring is the season of flowers. In March and April the rhododendron forests between 2,500 and 3,500 m burst into red, pink and white, especially between Lama Hotel and Ghoda Tabela in Langtang, around Sing Gompa on the Gosaikunda trail and below Tharepati in Helambu. Days are longer and warmer than in autumn, and lodges are open again after winter.
The trade-off is haze. By April, dust and smoke from the plains often cloud distant views by mid-morning, and afternoon cloud and showers become common in May. Early starts help. On the Manaslu Circuit, March can still carry deep snow on the Larkya La, so April is usually the better month. By late May the gorge of the Budhi Gandaki is hot and humid, and the first pre-monsoon storms arrive.
The monsoon: June to September
The monsoon brings most of the year's rain to these regions in four months. Trails turn muddy and slippery, leeches wait in the forests below about 3,000 m, and cloud hides the mountains for days at a time. The bigger problem is the road. The Pasang Lhamu Highway to Dhunche and Syabrubesi, the road up the Budhi Gandaki to Machha Khola and the roads into Helambu are all prone to landslides, and in June 2021 floods on the Melamchi river badly damaged Melamchi Bazaar.
There are reasons to go anyway. Janai Purnima, in July or August, is the one time to see the Gosaikunda pilgrimage, and many Nepali walkers make the trip in the rain. Upper Tsum lies partly in a rain shadow and is drier than the gorge below, though you still have to walk through the wet section to reach it. The hills are green, villages are busy planting rice and trails are empty. If you go, carry good rain gear, allow spare days and accept that plans will change.
- Pack a waterproof jacket and trousers, a pack cover and dry bags for clothes and electronics.
- Wear long socks and carry salt or repellent for leeches.
- Add at least one spare day for road delays each way.
- Expect fewer mountain views and plan to enjoy forests, villages and festivals instead.
- Check current status of roads and trails before you travel.
Shoulder weeks worth knowing
Some of the best walking falls just outside the peak weeks. The first half of December is often superb in the Langtang Valley and Helambu: the autumn crowds have gone, skies are still clear and the cold has not yet bitten hard. Late February and early March are similar for Helambu and the Tamang Heritage Trail, with bright days, empty lodges and the first rhododendrons opening at lower altitudes.
On the Manaslu side, the last days of September can be rewarding if the monsoon withdraws early, with green hillsides and waterfalls at full strength, but they are a gamble on the roads. Mid-November is often the sweet spot for the Larkya La: settled weather, thinner crowds at Dharamsala and only a little ice on the descent. Late May suits walkers who do not mind afternoon cloud and want the trails nearly to themselves, as long as they finish before the first heavy rains of June.
How to choose your dates
Start with what matters most to you, then match it to the calendar. Whatever you choose, keep a buffer day at each end of the trip for roads and weather, and check current status of permits, roads and festivals before you travel.
- Clear mountain views above all: mid-October to mid-November.
- Flowers and warmer days: late March to April.
- Fewest people: December, February or late May.
- Crossing the Larkya La: October, November or April.
- The Gosaikunda pilgrimage: Janai Purnima in July or August.
- Short holiday in winter: Helambu or the Chisapani rim walk.
Questions
What is the best month to trek in Langtang?
October is the most reliable month, with clear skies, dry trails and comfortable temperatures. November is equally clear but colder at Kyanjin Gompa. April is the best spring month, with rhododendrons in flower though hazier views. March, May and December are good alternatives. We avoid June to August because of the monsoon.
When is the best time for the Manaslu Circuit?
From early October to mid-November the Larkya La is usually clear of deep snow and the skies are at their best. April is the best spring month. March can still have heavy snow on the pass, and December to February often closes it. The monsoon months of June to August bring landslides in the Budhi Gandaki gorge.
Can I trek in Langtang in the monsoon?
It is possible but not ideal. Expect daily rain, leeches in the forest, cloud over the peaks and landslides on the road to Syabrubesi. Lodges stay open and the trail is quiet. If you go, add spare days, carry good rain gear and accept limited views. Late September is a better compromise than July or August.
Is the Larkya La open in winter?
Often not. From December to February snow frequently closes the Larkya La, and some lodges at Samdo and Dharamsala shut for the season. In mild winters crossings are possible with care, but you should have spare days and be ready to turn back. Check current status before you travel, and consider Tsum instead.
Is the Tsum Valley drier during the monsoon?
Upper Tsum lies partly in a rain shadow behind high ridges and gets noticeably less rain than the Budhi Gandaki gorge below. However, the approach from Machha Khola through the gorge is wet, slippery and prone to landslides in the monsoon. Tsum is better in the monsoon than many treks, but autumn and spring are still easier.
When do rhododendrons bloom in Langtang?
Rhododendrons usually flower from March to April, starting lower down and moving uphill as spring advances. The best displays are in the forests between Lama Hotel and Ghoda Tabela, around Sing Gompa on the Gosaikunda trail and below Tharepati in Helambu. Timing varies with altitude and each year's weather.
How cold is Kyanjin Gompa in December?
Very cold at night. In December, temperatures at Kyanjin Gompa often fall to around −10 °C or lower at night, while sunny days can reach a few degrees above freezing. Lodge rooms are unheated, so bring a sleeping bag rated to about −15 °C, a down jacket, thermal layers, a hat and gloves.
Do Dashain and Tihar affect trekking?
Yes. These festivals usually fall in October or early November. Roads and buses are crowded as people travel home, government offices close for several days, which can delay restricted area permits for Manaslu and Tsum, and some lodge staff take leave. Trekking continues normally, but plan permits and transport around the holiday dates.
What is the weather like at Gosaikunda in spring?
In March and April, days at Gosaikunda are often clear in the morning with cloud building in the afternoon. Temperatures range from about 5 to 10 °C in daytime sun to well below freezing at night. Snow can linger around the lakes and on the Laurebina La into April, so check conditions with your guide.
