JetBlue passengers hoping to travel on Monday, a national US holiday, are facing more delays and cancellations.
Cold weather and ice storms have delayed flights
The budget airline said it had cancelled some 25% of its 600 flights on Presidents' Day, but hoped to run a full flight schedule on Tuesday.
A snow storm on 14 February triggered hundreds of cancellations, which have had a knock-on effect since then.
The firm said it needed to cancel flights for an extra day to organise its operations.
The airline was also forced to cancel more flights to ensure JetBlue workers had the statutory required time off between shifts, spokesperson Sebastian White said.
The ice storm that hit the Midwest, then Northeast, last week meant many of the airline's 11,000 pilots and crew had been stranded, JetBlue chief executive David Neeleman told the New York Times.
Problems with the booking system had also contributed to the delays, he said.
The firm had planned to run more flights on 19 February than its usual Monday quota of 550 to 575 trips to enable it to cope with an increase in traffic on the public holiday.
Refunds for passengers whose flights were cancelled would be on a "case-by-case basis," the firm said.
News of hundreds of stranded passengers has prompted Congress to urge for a re-examination of laws concerning "passengers' bill of rights".
Shares in JetBlue - which says it is still assessing the financial impact of the delays - fell 2% by close of trade Friday, ahead of the three day weekend.