(USATODAY) — Southwest rolled out a 72-hour, nationwide fare sale Tuesday (June 2) in which the price of its flights are roughly based to distance. Dozens of the carrier’s shortest routes are available for fares of less than $100 round trip.

The sale covers travel from Aug. 25 through Dec. 16, though some holiday periods are blacked out. And bargain hunters must act quick; the sale concludes at the end of the day Thursday (June 4).

Southwest has previously rolled out similar fare sales in which fares were pegged to mileage thresholds. In past years, for example, Southwest ‘s sales priced flights of 500 miles or less at $49 each way and increased from there. Flights of 501 to 1,000 miles cost $99 each way and flights of 1,001 to 1,500 miles cost $129 each way. Flights of more than 1,500 miles went for $149 each way.

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