AirHint found the following cheapest return flights from Raleigh-durham (RDU) to Porto (OPO) in September 2025 (see full year).
Return flights
| 18 Sep - 25 Sep | Spirit Airlines | ||
| 04 Sep - 07 Sep | Frontier Airlines | ||
| 19 Sep - 11 Oct | Spirit Airlines | ||
| 27 Sep - 18 Oct | Frontier Airlines | ||
| 11 Sep - 04 Oct | Frontier Airlines |
Also check the deals for one-way flights from Raleigh-durham to Porto 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.
Find us on social media