AirHint found the following cheapest return flights from Helsinki (HEL) to Kathmandu (KTM) in September 2025 (see full year).

Return flights

04 Sep - 19 Sep	IndiGo
02 Sep - 22 Sep	IndiGo
01 Sep - 26 Sep	IndiGo
11 Sep - 25 Sep	IndiGo
03 Sep - 07 Oct	IndiGo
07 Sep - 15 Oct	IndiGo
08 Sep - 16 Oct	IndiGo
27 Sep - 28 Sep	IndiGo
25 Sep - 26 Sep	IndiGo
21 Sep - 26 Oct	Pegasus Airlines
11 Sep - 14 Oct	IndiGo
11 Sep - 21 Oct	IndiGo
15 Sep - 14 Oct	IndiGo
17 Sep - 19 Oct	IndiGo
23 Sep - 30 Oct	IndiGo
22 Sep - 30 Oct	IndiGo

Also check the deals for one-way flights from Helsinki to Kathmandu in September.

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

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Cheapest return flights from Helsinki to Kathmandu in September from 556€

Return flights