August is the cheapest month to fly this route, with average fares around $967 round trip.
Average round-trip fares by departure month, based on current availability.
| Month | Avg Price | Lowest | Relative Cost | |
|---|---|---|---|---|
| May 2026 | $1272 | $1025 | Peak | |
| June 2026 | $1202 | $1092 | ||
| July 2026 | $991 | $964 | ||
| August 2026 | $967 | $953 | Best |
Departing on Wednesday offers the lowest average fares at $1075. Friday departures are the most expensive at $1168, a difference of $93.
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 Chicago to Lisbon is August, with average round-trip fares around $967. The lowest fare found in August is $953.
Wednesday departures are the cheapest, averaging $1075 round trip. The most expensive day is Friday at $1168.
Based on current pricing trends, booking for August travel offers the best value. Avoid May if possible, as fares average $1272 compared to $967 in the cheapest month. June is a solid middle-ground option at $1202.
Flying in August instead of May can save you approximately $305 per round trip. The cheapest month averages $967 while the most expensive averages $1272.
Airlines, flight times, price calendar, and more for Chicago to Lisbon
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