The 2018 average domestic itinerary airfare of $350 was the lowest (adjusted for inflation) annual fare since such record keeping began in 1995. That number was down 1.8% from the previous low of $356 in 2017. However, the cost of flying hasn't decreased everywhere. According to the CompareCards.com report on airfare costs, the average airfare at 19 of the 100 largest U.S. airports actually increased year-over-year.

In the report’s key findings:

• Average airfare costs were down in 81 of the 100 largest airports, but there were some exceptions. Chicago-Midway airport saw the largest uptick in average airfare, increasing by nearly 7% from 2017 to 2018, while Chicago's O'Hare jumped 4%.

• Long Island MacArthur Airport in Long Island, Syracuse Hancock International and Portland International Airport had the largest decreases in average airfare costs. In each of those airports average airfare costs fell by over 10%.

• In general, flying out of the largest airports including Dallas/Fort Worth, Ronald Reagan Washington National, LaGuardia and Phoenix Sky Harbor International was more costly in 2018 compared to 2017.

Tips to Offset Travel Costs:

• Some cardholder perks may include free checked bags, companion passes, travel credits and airport lounge access, to name a few

•Plan ahead: airfares tend to increase leading up to the departure date, so it’s best to start shopping for flights well in advance of flying

• Be flexible with airports, dates, and number of stops: where and when you fly could equate to big savings.

• Travel light to avoid baggage fees and other costs. If you're not getting a free bag benefit through a credit card, try limiting the number of bags you check. Also, pack snacks for the flight.

"Flexibility is the key when it comes to keeping travel costs down," said CompareCards Chief Industry Analyst Matt Schulz. "If you're not tied to a specific airport, airline or set of dates and you might even be willing to go a little bit out of your way to get where you're going, you can really keep costs down. Credit card rewards can certainly help, too, especially cards with points that aren't tied to any particular airline."