December holiday airfares are continuing their creep upwards, according to priceline.com (Nasdaq: PCLN).  Based on the last two weeks of round-trip domestic ticket sales on priceline.com, the national average holiday airfare is $469, or 4% more expensive than airfares at this time last year.  The current national average airfare is also higher than it was a month ago, when travelers would have paid an average of $444 for their holiday tickets.  If purchased in early October, the average holiday fare was $430.
“We are now bumping up against that 21-day advance purchase window for airline tickets,” said priceline.com’s in-house Travel Ekspert Brian Ek.  “Typically, tickets are more expensive when the departure date is less than 21 days away, and they keep moving upward as the departure date gets closer.  For anyone who still has to buy holiday air tickets, the message is simple – the clock is ticking.”
Every year, priceline.com publishes a continuously updating Best Days To Fly calendar showing the days when travelers are most likely to find affordable fares.  The calendar can be found at http://www.priceline.com/promo/deals/winter_holidays/deals.html.

According to Priceline, the lowest fares for the upcoming holidays will probably be found for travel on December 17, 18, 25, 27 and 31.
Ek also had some additional tips to help find cheaper airfare and keep those travel costs down after the airfare is booked.

*  Pick times of the day that are normally less busy.  Time of day is important.  Travelers will find the most affordable seats departing early in the morning (5-7 a.m.) or late evening (after 8 p.m.).  Mid-day (11 a.m. – 4 p.m.) is a bit more expensive, but still reasonable.  Most expensive are the peak business travel hours (8-10 a.m. and 5-7 p.m.).

*  Try priceline.com’s Name Your Own Price® airline tickets service.  You can save even more on your airline tickets by using priceline.com’s Name Your Own Price® ticketing service.  With Name Your Own Price® tickets, travelers must agree to begin their trips anytime between 6:00 a.m. and 10:00 p.m. and there may be up to one connection each way. Visit http://www.priceline.com/flights/ and click on the link to use the service.

*  Send those presents on ahead.  You see presents; the airlines see extra baggage and maybe some extra fees.  Not to mention how unhappy the security screeners will be to see those wrapped boxes.  Save yourself the hassle by mailing or shipping presents in advance (after you’ve wrapped them, of course).
Weigh and measure your baggage.  Check your airline’s maximum requirements for checked and carry-on bags to make sure you won’t incur extra fees.  Note: baggage fees are charged separately for your outbound and return flights.