Long security lines are behind Philadelphia International Airport's ranking as the sixth-worst airport in North America, according to a new survey.

The travel website SleepingInAirports.net posted its rankings of the worst airports this month, and users voted Philadelphia as among the worst in North America.

The site wrote that "what really irritates travelers at PHL is the long security lines."

In the site's survey, travelers were asked to evaluate the airports on comfort, conveniences, cleanliness and customer service.

Besides lengthy waits for security, storms and staff also contributed to PHL's number-six ranking.

"Couple that with some not-so-pleasant staff, and you're sure to have enough unhappy people fly away from this airport," the site wrote. "Furthermore, Philadelphia happens to be subject to its fair share of winter storms."

But, on the plus side, the website noted that the airport has a "decent variety" of restaurants, wifi access and pillows and blankets available for travelers.

New York City's LaGuardia International Airport was named the worst in North America. No other Pennsylvania travel hubs made the list, but Newark Liberty International Airport in New Jersey was rated fourth.

Worldwide, the Islamabad Benazir Bhutto International Airport, Pakistan in Pakistan was named the worst airport.

The Singapore Changi International Airport was ranked the best in the world, while Canada's Vancouver International Airport was picked as the top North American airport.