Delhi to Kathmandu: Air India vs IndiGo fares in 2026 — and the cheapest month to fly
By Aarav Sharma (Aarav Sharma covers Indian airline operations, airport infrastructure and route economics. He writes about Tier-1 and Tier-2 airport developments, IndiGo and Air India fleet strategy, and the unsung Indian aviation hubs travellers should know about.) · Published · 9 min read
On the Delhi–Kathmandu route, Air India has quietly become the price leader — partly because it treats Nepal as a prestige international market where filling seats matters more than squeezing yield. January and August are consistently the cheapest months, and booking around 40 days out tends to hit the sweet spot before fares jump for festival travel.
TL;DR — the short answer
On the Delhi–Kathmandu (DEL–KTM) route in 2026, Air India typically prices lower than IndiGo on a like-for-like basis — often by a meaningful margin — particularly when you factor in Air India’s included checked baggage on international fares. The cheapest months to fly are January (post-New Year lull, Himalayan views at their clearest) and August (off-season pricing despite being monsoon, when fewer leisure travellers commit). If you’re booking for either of those windows, aim for roughly 40 days ahead. That’s the sweet spot before Dashain and Diwali fares kick in for the October–November crunch.
Why does Air India beat IndiGo on this route?
It’s counterintuitive at first. IndiGo dominates almost every domestic Indian route on price. But Delhi–Kathmandu is a short international sector — about 90 minutes of flying — and the competitive dynamics are different from, say, Delhi–Mumbai.
Air India (which absorbed Vistara’s operations in 2024 and has been rationalising its network since) runs Delhi–Kathmandu as a flag-carrier route with strong bilateral significance. It often deploys aircraft that would otherwise sit on the ground between longer rotations, effectively pricing these seats to fill rather than to maximise yield. The airline also benefits from through-ticketing with connecting long-haul passengers on its international network.
IndiGo entered the Kathmandu route more aggressively and has decent frequencies, but its cost structure on international operations — airport fees, crew accommodation, international handling — doesn’t give it the same advantage it has on domestic routes. The result: IndiGo’s base fares are competitive, but once you add a 15-kg or 20-kg bag (which most travellers to Nepal want), Air India’s all-in cost often comes out cheaper.
Nepal Airlines also operates Delhi–Kathmandu, and occasionally their fares are the lowest of all — worth checking if you’re flexible and can find them on a metasearch like FlightGPT. The catch is that their schedules can be thinner and disruptions more frequent, so factor that in.
Which months are cheapest for Delhi–Kathmandu flights?
The fare curve on this route is fairly predictable if you understand what drives Nepal’s tourist calendar.
- January: Post-Christmas and New Year international traffic dies down. Kathmandu’s streets are calm. Himalayan visibility is excellent on clear winter days. Fares are typically at their lowest in the first three weeks of January. If you’re not after trekking season (that’s October–November), January is the best bet for a city trip or Pokhara visit.
- August: Monsoon has set in properly. International tourists avoid Nepal in August. That keeps fares depressed despite it being school-holiday season in India — Indian families tend to head to hill stations domestically rather than to Kathmandu in the rain. If you don’t mind some showers and want to see a very local, un-touristy Nepal, August offers genuinely low fares.
- October–November: The most popular trekking season — and the most expensive. Dashain and Tihar (Nepal’s equivalent of Diwali) fall in this window too. Fares spike significantly. If you must fly in October or November, book at least 60–70 days ahead.
- March–April: Second trekking season (rhododendrons blooming, Annapurna Circuit accessible). Fares are moderate — not as high as autumn, but not cheap either. Book 45–50 days out.
The 40-day booking rule explained
On DEL–KTM, fare data consistently shows a pattern: tickets priced around 35–45 days before departure tend to be meaningfully cheaper than last-minute fares (which spike 40–70% in the two weeks before travel) but also cheaper than the very earliest fares (airlines often test the market with slightly higher opening prices before dropping to fill seats).
The sweet spot is roughly 40 days out — long enough that capacity is still available and the airline hasn’t yet started protecting seats for high-yield last-minute bookings, but close enough that the flight exists as a concrete object in the world and the airline wants it to fill. For January or August travel, hitting that 40-day window often means you catch the low-demand period before any adjacent festival or school holiday nudges prices up.
One tactical note: if you’re travelling around Holi (February–March) or any Indian national holiday that creates a long weekend, the 40-day rule still applies but compress it — those long weekends fill Delhi–Kathmandu surprisingly fast. Search flexible dates on FlightGPT to see the fare spread across a 2-week window at once.
Baggage: where the real price difference shows up
This is where Air India’s advantage crystallises. As of 2026, Air India’s standard international economy fares on short regional routes typically include at least 15–23 kg of checked baggage (verify the exact allowance in your fare conditions at booking — it varies by fare bucket and can change). IndiGo’s base fare on international routes is usually baggage-free, with bag fees added on top. On a route to Nepal where most travellers are either tourists with gear or Indian families visiting relatives, very few people are flying carry-on only.
Before declaring a winner on price, always compare the ‘all-in fare with one checked bag’ across both airlines. It’s a 5-minute exercise on the respective booking sites that can save you a few hundred to a couple of thousand rupees — especially on the return leg when bags are heavier.
Visa and immigration: one less thing to worry about
Indians don’t need a visa for Nepal — the India–Nepal open border treaty means Indian passport holders can enter without a visa or any fee. You don’t need to factor in visa costs when comparing this route to, say, a flight to Sri Lanka or Bhutan (where Indians need a permit or visa). Carry your Indian passport or a valid government-issued photo ID (an Aadhaar card is typically accepted for Indian nationals entering Nepal by air, but check the airline’s specific requirements since this can change — your passport is always the safest document).
At Kathmandu’s Tribhuvan International Airport, immigration for Indian nationals is usually a separate, faster lane. The airport is small by Indian metro standards, so plan to be there about 90 minutes before departure on the return.
Bottom line
If you’re comparing Air India and IndiGo for Delhi–Kathmandu, price Air India first — it’s genuinely competitive and often cheaper all-in once you add a bag. Fly in January or August for the lowest fares; book around 40 days out for the best combination of price and availability. Avoid the October–November window unless you’re committed to trekking season and book far in advance. Check current fares across both airlines (and Nepal Airlines) via FlightGPT, then compare with a bag added in on the airline’s own site. Also worth reading: our pieces on India–Maldives cheapest airline and month and Ahmedabad to London: Air India vs Gulf hubs.
Frequently asked questions
Is Air India cheaper than IndiGo for Delhi to Kathmandu?
Often yes, particularly on an all-in comparison including checked baggage. Air India’s standard international economy fares on short regional routes typically include baggage, while IndiGo charges separately. Run a side-by-side check with one 15-kg or 20-kg bag added on both — Air India frequently wins. Nepal Airlines is also worth checking for occasional lower fares.
What is the cheapest month to fly Delhi to Kathmandu in 2026?
January (first 3 weeks) and August are consistently the cheapest months on this route. October and November are the most expensive due to Nepal’s trekking season and the Dashain–Diwali festival window. Fares in the peak period can be 50–80% higher than January lows.
How early should I book a Delhi–Kathmandu flight?
Around 40 days ahead is typically the sweet spot for standard travel dates. For October–November (trekking season, Dashain, Diwali), book 60–70 days out. For travel around Indian long weekends or school holidays, the same urgency applies — those dates fill faster than the route’s low-season baseline suggests.
Do Indians need a visa for Nepal?
No. Indian passport holders can enter Nepal without a visa under the India–Nepal open border arrangement. Your Indian passport is sufficient; an Aadhaar card may also be accepted at Kathmandu airport but check the airline’s current document requirements before you travel.
Does Nepal Airlines fly Delhi–Kathmandu? Is it reliable?
Yes, Nepal Airlines operates the route and occasionally offers the lowest base fares. However, the airline has a thinner schedule and a history of disruptions — delays and occasional cancellations at short notice. Factor in your itinerary’s flexibility when comparing it against Air India or IndiGo. For last-minute or time-sensitive travel, Indian carriers are generally more reliable on this route.
What is the flight time from Delhi to Kathmandu?
Around 90 minutes in the air. Given it’s a short sector, the difference in airport experience and boarding efficiency matters as much as in-flight comfort. Tribhuvan International Airport in Kathmandu is a single-runway airport in a valley — morning slots tend to have fewer weather-related delays than afternoon arrivals.