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

Return flights

08 Sep - 15 Sep	Cathay Pacific
09 Sep - 24 Oct	Air India
27 Sep - 11 Oct	Asiana Airlines
26 Sep - 25 Oct	Air India
27 Sep - 25 Oct	Asiana Airlines
27 Sep - 26 Oct	Air India
28 Sep - 26 Oct	Air India
30 Sep - 31 Oct	Air India
13 Sep - 14 Sep	IndiGo

Also check the deals for one-way flights from San Francisco 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 San Francisco to Kathmandu in September from 783€

Return flights