AirHint found the following cheapest return flights from San Diego (SAN) to Frankfurt (FRA) in September 2025 (see full year).

Return flights

09 Sep - 23 Sep	Lufthansa
09 Sep - 16 Sep	United
03 Sep - 10 Sep	United
29 Sep - 06 Oct	Air Canada
16 Sep - 23 Sep	United
15 Sep - 22 Sep	Hawaiian Airlines
01 Sep - 08 Sep	Air France
11 Sep - 18 Sep	United
06 Sep - 20 Sep	WestJet
05 Sep - 12 Sep	United
07 Sep - 14 Sep	United
28 Sep - 05 Oct	Air Canada
25 Sep - 02 Oct	United

Also check the deals for one-way flights from San Diego to Frankfurt 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 Diego to Frankfurt in September from $420

Return flights