When to film in Nepal

There are also two calendars running at once. Flights, visas and hotels work on the Gregorian year. Festivals and public holidays mostly work on lunar reckoning inside the Bikram Sambat calendar, which means the dates you need move by weeks from one year to the next, and the weeks when government offices effectively close move with them.

Altitude adds a third dimension. The same week that is warm and open at 800 metres can be closed by snow at 5,000, so a national calendar is only ever half the answer. The other half is the height your unit will actually stand at, and how fast it gets there.

What follows is the shape of the year as a scheduling problem: season by season, then month by month, with the light, the flights, the festivals and the altitude all read together. Conditions, rules and flight arrangements in Nepal change, so treat every item here as a starting point to verify against the current position rather than a settled fact. Nothing below is a promise about weather, access or approval.

Nepal runs from around 60 metres in the Terai to over 8,800 metres in a horizontal distance of about 200 kilometres, so a single date means four different climates depending on where the unit is standing. The monsoon is the organising fact. It usually arrives from the east around the middle of June and withdraws through late September, and every other window is defined by its distance from that. Autumn is the clean air that follows the rain. Winter is the cold, dry high pressure that follows autumn. Spring is the warming, dust-loading run up to the next monsoon. Read the calendar from the rain outward and the rest falls into place.

Those four windows are not four equal quarters. The clear post-monsoon spell that everyone wants is short, perhaps six to eight weeks. The pre-monsoon haze can settle in for a couple of months. The monsoon itself is long and the deep-cold heart of winter is narrow. So the honest planning unit is not the season, it is the window inside the season, and it moves a little every year with the timing of the rains.

The country is also three countries stacked north to south. The Terai is subtropical plain that shares its weather with the Gangetic north of India. The middle hills, where most of the towns, temples and terraced valleys sit, are temperate and this is where haze and cloud do the most damage to a mountain shot. The high Himalaya and the trans-Himalayan valleys behind them are alpine and then near-desert. A schedule that crosses all three in a fortnight is really three schedules, and each has its own rules for light, travel and comfort.

Daylight matters more than producers expect. Kathmandu sits near 28 degrees north, so the day swings from roughly ten and a half hours around the winter solstice to about thirteen and a half in June. The almanac is optimistic. In a steep valley the sun clears the ridge late and drops behind it early, and a north-facing valley floor in December can give you five or six hours of usable light with a long, flat, cold shadow either side. When you scout, note the ridge line, not just the sunrise time, and note which way the valley faces, because a south-facing slope and the north-facing slope across from it are on completely different clocks.

The other constant is the morning. Convective cloud builds from late morning, valley winds get up, and haze settles into the middle distance. Long lens work, aerials, drone and mountain flights belong in the first hours of the day, all year round. Put dialogue, interiors and pick-ups in the afternoon and you will lose far less. This is the single most reliable rule in Nepal scheduling, and it holds in every season: the mountains are a morning subject and almost everything else is flexible around them.

Golden hour is not evenly useful either. Morning light in Nepal is usually the cleaner of the two, because the air has settled overnight and the dust and smoke of the day have not yet risen. Evening can be warmer in colour but hazier in fact. If a hero mountain shot has to be golden, plan it for dawn and treat any evening version as a bonus rather than the plan.

The weeks after the monsoon withdraws are the cleanest air Nepal gets. The dust has been washed out, high pressure is comparatively stable, temperatures at altitude are workable, the hills are still green in October and the passes are usually open. It is also when Dashain, Tihar and, in the Khumbu, Mani Rimdu at Tengboche fall.

The constraint here is not weather, it is availability. Trekking groups, expeditions, stills crews and broadcast units all want the same six weeks. Domestic seats, mountain lodges, vehicles and experienced local crew get committed a long way out. If you decide on this window late, what you lose is options rather than anything you can fix on the ground. The earlier you commit, the more of autumn you actually get to use.

Autumn is not a clear-sky guarantee either. Late cyclones in the Bay of Bengal have pushed heavy out-of-season snow and rain into the high country in October, closing passes and grounding flights for days. Building a tight schedule with no slack because the calendar says October is a common and expensive mistake. The window is the best odds of the year, not a certainty, and the difference between odds and certainty is exactly the number of weather days you carry.

One caveat for the Terai. After the monsoon the grass in Chitwan and Bardia is at its tallest, so wildlife sightlines in October are poor even though the light is excellent. If the film is wildlife rather than landscape, the good Terai months and the good mountain months are not the same, and autumn favours the mountains.

Winter is underrated for anything that needs stable air and empty locations. Skies are often very clear, snow sits properly on the peaks, and the trails, monasteries and viewpoints that are congested in autumn are quiet. Crew and vehicles are easier to secure, and the light, though short, is beautifully hard and clean in the middle of the day.

What you pay for it is daylight and access. High passes including Thorong La, Larke La and the Cho La and Renjo La side of the Khumbu can be blocked by snow or turn serious with little warning. Many high lodges close or run with minimal staff. In Upper Mustang and parts of Manang, families traditionally move to lower ground for the winter, so whole settlements thin out. If the story needs upper-valley village life, deep winter is the wrong time to ask for it.

Fog is two separate problems and they contradict each other. The Kathmandu Valley gets winter inversions that hold pollution down and delay morning departures. The Terai gets dense radiation fog that can hold up flights into Bharatpur, Bhairahawa, Simara and Nepalgunj for hours and makes the east-west highway slow at night. In the hills you fly early. In the Terai in midwinter, early is the problem, because the fog often clears only by mid to late morning. A schedule that moves between the two needs both rules written into it, and the same call time that is right in Pokhara can be wrong in Bharatpur on the same morning.

Winter is also when community grass cutting happens in the Terai parks, and sightlines open up considerably afterwards. Wildlife remains wildlife. Nobody can promise you a tiger, but your odds of seeing across open ground are far better in the late-winter parks than in the tall grass of autumn.

Spring gives you long days, comfortable temperatures at altitude and rhododendron. The bloom moves up the hill with the season, generally starting in the lower forests and working higher into April and May, and the exact week in any given valley depends on that year’s winter. Treat a bloom date as a range you might miss, not a fixture you can build a call sheet around.

The risk is visibility. Through the dry pre-monsoon, dust, crop residue burning and hill and forest fires load the air across the middle hills and the Terai. In a bad spring the Himalaya are simply not there from viewpoints below them for days on end. If the film depends on seeing the range from Nagarkot, Poon Hill, Sarangkot or a middle-hills village, spring carries more visibility risk than any other window, including monsoon in the rain shadow. Build alternatives, or go higher and get above it. A viewpoint at 3,000 metres or above will often sit over the worst of the murk when a viewpoint at 1,500 metres is looking into a wall of it.

What spring does own: this is the main climbing season on Everest and the other 8,000 metre peaks, so base camps are occupied and the high routes are populated in a way they are not in autumn. It is also when the Terai is hot and dry, water is scarce, grass has been cut or burnt back and wildlife concentrates at the remaining water. Bisket Jatra in Bhaktapur falls around the Nepali new year in mid-April, Buddha Jayanti lands on the Vaisakha full moon, and the Rato Machhindranath chariot procession in Patan runs across weeks in the spring. Afternoon thunderstorms start building from late April, which is a warning for aerials and a gift for anyone who wants dramatic cloud.

The monsoon takes away predictability. Domestic flights cancel, roads take landslides, and the Prithvi and Narayanghat corridors can close and strand a unit for days. Cloud sits on the hills for a week at a time. Forests have leeches. Humidity gets into optics, and anything not sealed and silica-packed will suffer.

What it gives you exists nowhere else in the calendar. Rice transplanting runs through late June and July, the terraces are the green they are famous for, waterfalls carry real volume, cloud moves through the valleys, and the Terai floods. If the subject is water, agriculture, climate, migration or the season itself, this is the only window. The tail of the monsoon also carries Teej and, in Kathmandu, Indra Jatra.

North of the main Himalayan range, Mustang, Dolpo, Manang, Nar Phu and Humla sit in the rain shadow and get a fraction of the rainfall. Conditions up there can be workable through July and August. The catch is the doors. You reach them through Pokhara, Nepalgunj or the road up the Kali Gandaki gorge, all of which are inside the monsoon. Plan those legs as fully weather-contingent and put spare days at each end rather than in the middle, so a delayed door does not eat the days you needed for the dry country beyond it.

One local rule worth knowing: the up-valley wind in the Kali Gandaki gets strong from late morning, so Jomsom flights and drone work there are a morning task in every season. Off-peak has advantages too. Crew, vehicles and lodges are available, and the locations that are shoulder to shoulder in October are empty, so if the film can absorb the disruption it can also enjoy the space.

The national seasons are only half the story. The other half is height. A week that is warm and open at 800 metres in the middle hills can be shut by snow at 5,000 metres on the same day, and the calendar you actually shoot to is the one for the altitude band your unit will stand at, not the one for the country as a whole.

Up high, the usable window narrows to two shoulders on either side of the monsoon: broadly late spring before the rains, and autumn after them. High passes such as Thorong La, Larke La and Cho La are generally crossable from around April into early June and again from late September into November, and never as a certainty, because a single storm can close them out of season in either direction. Between those shoulders, deep winter locks the high routes with snow and cold, and the monsoon buries them in cloud even where the trails stay open.

Altitude also flips the meaning of a season. Deep winter empties the high villages of Mustang, Manang and the upper valleys as families move to lower ground, so the very window that gives you the cleanest air down in the hills takes upper-valley life out of reach. Monsoon, meanwhile, is the disaster for the middle hills but the working window for the trans-Himalayan north, where the rain shadow keeps Mustang and Dolpo comparatively dry through July and August. If the film lives above about 3,000 metres, plan its calendar first and fit the low-altitude days around it, not the other way round.

There is a schedule cost as well as a calendar one. Gaining height quickly costs you people, not time, so acclimatisation days are structural, not padding, and they land inside whatever window you have chosen. That interacts with the season: the short days of winter and the afternoon storms of late spring both eat into the hours you have to move safely between camps. The deeper mechanics of pacing, health and evacuation are a subject in their own right and belong on the filming-at-altitude guide, but for scheduling the point is simple. The higher the film goes, the shorter and firmer its window becomes.

Nepal’s official calendar is Bikram Sambat, roughly 56 to 57 years ahead of the Gregorian calendar, with the new year in mid-April. Most festivals are fixed by lunar reckoning, so their Gregorian dates shift by weeks year to year. Never carry a festival date across from a previous schedule. Check the current year’s Nepali calendar, the patro, and check which day of a multi-day festival actually carries the event you want, because the procession, the sacrifice, the masked dance and the immersion are often days apart.

A few sit closer to the solar calendar and hold roughly steady, such as Maghe Sankranti in mid-January and Bisket Jatra around the new year. Others can move while they are happening. The Rato Machhindranath jatra in Patan has been delayed and rescheduled mid-procession. Treat a festival as a window, not a date, and do not book a departure flight against its last scheduled day.

Dashain and Tihar are the scheduling event of the year. They fall inside the same autumn window everyone wants, and the country slows for an extended stretch across the two. Government offices, banks and many businesses close or run skeleton staff, people travel to their home districts so drivers and vehicles are committed and the roads out of Kathmandu are heavy, and Chhath follows in the Terai. Anything that needs a signature, a filming permission, an area permit, a drone approval or customs clearance on incoming gear should be finished well before that period, not chased through it.

Note also that the office week is not Monday to Friday: Saturday is the weekly holiday and Friday can be a short day, so a week of processing is not five working days. The working week has been changed by government decision before, so confirm the current position. Mid-July also sits at the end of the Nepali fiscal year, which occupies offices with their own year-end. Festivals can be something to plan toward as much as around: if the film wants Dashain, Tihar, Indra Jatra or Mani Rimdu as content, the date moves to the centre of the schedule and everything else arranges itself around it.