By David Shepardson

WASHINGTON (Reuters) -U.S. airlines have canceled 1.6% of all flights this year despite record summer travel and significant disruptions in July sparked by cybersecurity firm CrowdStrike, the Transportation Department said on Thursday.

USDOT said the cancellation rate through Tuesday this year is slightly above the 1.5% cancel rate for 2023 but lower than any other year since 2017 when it was 1.4%.

The Transportation Security Administration said last week that U.S. summer travel has set a new record and is forecasting record passenger levels for the Labor Day travel period that marks the end of the summer season.

The TSA is forecasting it will screen 17 million air travelers between Thursday and Sept. 4, up 8.5% over the same holiday period last year. Airlines for America, a trade group, said carriers plan to have 3.3% more seats departing U.S. airports through Monday over 2023.

FlightAware and the airline group said carriers canceled less than 100 flights on Thursday — or less than 0.5% of flights, but the Federal Aviation Administration warned afternoon weather may cause delays at some airports.

The TSA screened 3.01 million airline passengers on July 7, the highest number ever on a single day and the first time it surpassed 3 million.

The software update last month by global cybersecurity firm CrowdStrike triggered system problems for Microsoft customers, including many airlines, and led to thousands of flight cancellations.

Delta Air Lines canceled about 7,000 flights over five days, affecting 1.3 million customers and taking much longer than other carriers to recover.

The FAA is still working to address a persistent shortage of air traffic controllers.

In June, the FAA said it was again extending cuts to minimum flight requirements at congested New York City-area airports through October 2025, citing air traffic controller staffing shortages. Last month, the FAA required 12 air traffic controllers in New York to relocate to Philadelphia for up to two years to shift some New Jersey airspace responsibility.

(Reporting by David Shepardson; editing by Jonathan Oatis)