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

Return flights

04 Sep - 18 Sep	IndiGo
05 Sep - 21 Sep	IndiGo
19 Sep - 27 Sep	IndiGo
06 Sep - 14 Sep	IndiGo
04 Sep - 31 Oct	IndiGo
05 Sep - 30 Sep	IndiGo
30 Sep - 31 Oct	IndiGo
15 Sep - 04 Oct	IndiGo
29 Sep - 31 Oct	IndiGo
28 Sep - 30 Oct	IndiGo
29 Sep - 30 Oct	IndiGo
27 Sep - 31 Oct	IndiGo
27 Sep - 29 Oct	IndiGo
29 Sep - 29 Oct	IndiGo
17 Sep - 29 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.

Book a cheap hotel in Kathmandu

Cheap car rent in Kathmandu

Cheapest return flights from Helsinki to Kathmandu in September from $808

Return flights