U.S. airlines canceled high numbers of flights for a second straight day on Friday as they tried to recover from storms while accommodating growing crowds of summer vacationers.

By midmorning in the eastern U.S., airlines has scrubbed more than 1,000 flights after canceling more than 1,700 on Thursday, according to tracking service FlightAware.

Airports with the most cancellations those in Charlotte, North Carolina, a major hub for American Airlines, LaGuardia and Newark Liberty in the New York City area, and Reagan Washington National outside Washington, D.C.

On Thursday, Transportation Secretary Pete Buttigieg held a virtual meeting with airline CEOs to go over steps the airlines are taking to operate smoothly over the July 4 holiday and the rest of the summer, and to improve accommodation of passengers who get stranded when flights are canceled.

Over the Memorial Day holiday weekend that typically kicks off the summer travel season, airlines struggled with bad weather and shortages of workers, especially pilots, leading to cancellations.

So far in June, more than 2.2 million travelers a day on average have gone through security checkpoints at U.S. airports. That’s down 13% from the same period before the pandemic.