August is the cheapest month to fly this route, with average fares around $1197 round trip.
Average round-trip fares by departure month, based on current availability.
| Month | Avg Price | Lowest | Relative Cost | |
|---|---|---|---|---|
| May 2026 | $1488 | $1232 | Peak | |
| June 2026 | $1331 | $955 | ||
| July 2026 | $1287 | $1129 | ||
| August 2026 | $1197 | $1117 | Best |
Departing on Tuesday offers the lowest average fares at $1170. Sunday departures are the most expensive at $1445, a difference of $275.
The best time to fly is August. Set up an alert and we'll notify you when prices drop.
Get Started Free →The cheapest month to fly from Philadelphia to Lisbon is August, with average round-trip fares around $1197. The lowest fare found in August is $1117.
Tuesday departures are the cheapest, averaging $1170 round trip. The most expensive day is Sunday at $1445.
Based on current pricing trends, booking for August travel offers the best value. Avoid May if possible, as fares average $1488 compared to $1197 in the cheapest month. June is a solid middle-ground option at $1331.
Flying in August instead of May can save you approximately $291 per round trip. The cheapest month averages $1197 while the most expensive averages $1488.
Airlines, flight times, price calendar, and more for Philadelphia to Lisbon
View PHL → LIS Details