The second largest airline in Canada has fallen behind in the past two months when it comes to getting its passengers to their destinations on time, according to a report released this week.

Calgary-based WestJet, which operates many of its flights from Pearson Airport in Mississauga, has ranked last again in the ranking that tracks on-time performance for 10 major airlines in North America month to month.

The Canadian airline had 60.85 percent of its 18,424 flights in July arrive on time, meaning nearly 40 percent, or 7,185 flights, arrived late at their destination, according to the latest on-time performance report from aviation data company Cirium (see charts below).

The report noted that a flight is considered late if it lands 15 minutes or more after its scheduled arrival time.

By comparison, Florida-based Spirit Airlines ranked ninth in July with an on-time performance rate of 65.19 percent (from 27,153 flights).

Air Canada, which operates more flights from Pearson than any other airport, ranked seventh in the latest list, with 65.52 percent of its 35,820 flights arriving on time last month.

The largest airline in Canada has consistently ranked in the lower half of Cirium's monthly rankings, often landing in 10th place.

In June, Air Canada landed 69.6 percent of its 33,373 flights on time, placing it ninth among the largest airlines in North America.

Meanwhile, Denver-based Frontier Airlines ranked eighth in the July ratings (65.3 percent of 21,013 flights on time).

For WestJet, the latest showing represents a significant drop from the rankings in April and May, when it ranked second and third, respectively.

WestJet's figures in May were 77.55 percent from a total of 16,348 flights, and April data showed the airline had 82.7 percent of its 15,085 flights landing on time.

In June, Canada's second-largest airline ranked seventh on the list (71.95 percent of 16,876 flights were on time), a position more consistent with WestJet's historical performances.

In both February and March, WestJet ranked 10th in the on-time performance list, according to Cirium.