This summer could be one of the cheapest in recent memory to fly.

Airlines are aggressively slashing ticket prices to fight a falloff in travel caused by the recession.

Data analyzed by giant Internet travel site Travelocity.com for USA TODAY show fares over the Memorial Day holiday weekend -- the start of the summer season -- are down sharply from last year.

The average domestic round-trip airfare booked for the holiday on Travelocity as of last Monday is $295, down about 10% from a year ago.

Fares booked to many popular destinations are down even more. The average fare to Washington, D.C., over Memorial Day weekend, for instance, is down 18% year over year.

The average Travelocity-booked fare for international flights over Memorial Day weekend is $610 round trip, down 14% from $713 last year and down 16% from 2007. The fare to London is down 20%; Paris is down 33%.

Year-over-year comparisons may be exaggerated because higher jet fuel prices last year drove up spring fares. Still, the reductions are "remarkable," says Genevieve Brown, senior editor for Travelocity. "For the last few years, we have seen increase after increase. But this is a peak travel weekend for the airlines, and they have to get people in these seats."