(WN) Southwest Airlines 3521 On-Time Performance Rating

Date Range:

15-May-2026 to 15-Jul-2026

(MDW) Chicago Midway International Airport

Chicago, IL, US

(BOS) Boston Logan International Airport

Boston, MA, US

On-Time Performance Chart

(using rounded numbers)

On-Time

50%

Late

Very Late

33%

Excessive

17%

Cancelled

Diverted

Delay Statistics

(Aggregate Arrival Delay Statistics for this Flight)

Total Flights Observed

Total Delays ( > 1 min )

Codeshares

Average Delay (min.)

54.5

Standard Deviation

56.8

Min

Max

137

WN 3521 On-Time Performance Details

Overall Rating

0.9 of 5

Poor

Percentage On-Time 50%

Average Delay Time 54.5 min

FlightStats Rating is a merit measurement considering both on-time performance and delay severity. The score, 0.9 shows that this flight has on-time performance characteristics better than 16% of all other flights in the FlightStats database.

On-Time Performance Rating

0.3 of 5

Very Poor

Percentage On-Time 50%

This flight has an on-time performance of 50%. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight is on-time more often than 7% of other flights.

Delay Performance

1.4 of 5

Poor

Average Delay Time 54.5 min

This flight has an average delay of 54.5 minutes with a standard deviation of 56.8 minutes. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight has delay performance characteristics better than 27% of other flights.