To save up to 39% on this flight, we recommend booking at least 61 days prior to travel. The price may fluctuate and will likely increase closer to your departure date. Users on Cheapflights have found tickets from Portland to Gimpo Intl from $1,193 1-2 weeks out and tickets from $1,211 for flights departing within the next 72 hours.
Due to multiple factors, expect to potentially pay more when booking in June. For low rates, April can be a great choice for travel to Gimpo Intl. Flights to Gimpo Intl from Portland in April are about $1,098 on average during April, but can be found for as low as $549.