Could this be the worst summer for air travel? The Federal Aviation Association (FAA) released a report, saying that passengers across the country are experiencing flight delays. And statistics from FlightStats.com, a flight-tracking service, show that June was one of the worst months in U.S. history.

Last year, there were 8,710 canceled flights in June. This year, in the same month, the number more than doubled to 20,301 flights which ended up in cancellation. From 40 of the largest airlines, 30% of the flights scheduled to land in the U.S. were delayed in June, with delays lasting an average of one hour.

Some blame the FAA, which is responsible for operating the nation’s air-traffic-control system.

“Consumers are fed up now and the airline industry is taking the heat,” said aviation analyst Mike Boyd of the Boyd Group to The Associated Press. “They’re taking the heat because they never pressured the FAA to fix the system.”

Airlines now complain that the FAA isn’t satisfying the needs of the nation’s growing travel demand with their obsolete equipment. So what do the airlines do? According to FlightStats.com, the 40 major airlines scheduled 14% more flights in June of this year than of last year. The increase consists of smaller jet planes that are cheaper and can make multiple trips, but still, they add to the traffic and they flood key airports, which is why others blame the airlines.

But regardless of who is to blame, there are still other major factors.

“When you couple the bad weather with the increase in traffic, it’s a snowball effect,” says Mike Sammartino, the FAA’s director of system operations to The Wall Street Journal.

When thunderstorms hit the U.S., the Canadian airspace is usually used as an asylum for U.S. planes to escape severe weather. However, with storm problems of their own, Canada’s air-traffic officials denied access into their airspace, adding to the problems with flight delays for June travelers.

Travelers also have to deal with rebooking delayed or canceled flights, which airlines are sometimes unable to do. This left hundreds of thousands waiting for hours, and even days. Some booked hotels and others spent the night in the airport’s public terminals.

American Airlines, one of the top ten biggest U.S. airlines, had the most delays in June. Only 58% of its arrivals were on time, and of the delayed flights, 21% of them were over 45 minutes late. American Airlines says this is four times as many cancellations than of June 2006.

Though it may seem we are having a bad summer for air travel so far, it doesn’t mean we’re having a bad summer.