Flight WN4321
Southwest Airlines flight WN4321
Looking for WN4321 in the air…
Alerts at this flight's airports
Baltimore (BWI) to Islip (ISP)
Historically, this flight arrives 15+ minutes late 47% of the time, and when it is late the delay averages 71 minutes. It was cancelled 5.0% of the time.
- On-time arrivals
- 52.6%
- Less than 15 minutes late
- Cancelled
- 5.0%
- Of scheduled flights
- Average delay when late
- 71 min
- Flights arriving 15+ minutes late
- Flights tracked
- 60
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 70%
- Airline (crew, maintenance, cleaning) 24%
- Air traffic control & airport 4%
- Extreme weather 3%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Sacramento (SMF) to Burbank (BUR)
Historically, this flight arrives 15+ minutes late 9% of the time, and when it is late the delay averages 85 minutes. It was cancelled 6.5% of the time.
- On-time arrivals
- 90.7%
- Less than 15 minutes late
- Cancelled
- 6.5%
- Of scheduled flights
- Average delay when late
- 85 min
- Flights arriving 15+ minutes late
- Flights tracked
- 46
- Scheduled flights in the period
What caused the delays
- Air traffic control & airport 59%
- Late-arriving aircraft 35%
- Extreme weather 4%
- Airline (crew, maintenance, cleaning) 2%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Santa Ana (SNA) to Nashville (BNA)
Only 13 flights on record, which is too few for reliable odds.
- On-time arrivals
- 61.5%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 26 min
- Flights arriving 15+ minutes late
- Flights tracked
- 13
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 52%
- Late-arriving aircraft 29%
- Air traffic control & airport 19%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Norfolk (ORF) to Baltimore (BWI)
Only 12 flights on record, which is too few for reliable odds.
- On-time arrivals
- 83.3%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 36 min
- Flights arriving 15+ minutes late
- Flights tracked
- 12
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 95%
- Late-arriving aircraft 5%
- Air traffic control & airport 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Baltimore (BWI) to Miami (MIA)
Only 11 flights on record, which is too few for reliable odds.
- On-time arrivals
- 90.0%
- Less than 15 minutes late
- Cancelled
- 9.1%
- Of scheduled flights
- Average delay when late
- 26 min
- Flights arriving 15+ minutes late
- Flights tracked
- 11
- Scheduled flights in the period
What caused the delays
- Air traffic control & airport 100%
- Airline (crew, maintenance, cleaning) 0%
- Late-arriving aircraft 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Fort Lauderdale (FLL) to Las Vegas (LAS)
Only 5 flights on record, which is too few for reliable odds.
- On-time arrivals
- 60.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 46 min
- Flights arriving 15+ minutes late
- Flights tracked
- 5
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 59%
- Airline (crew, maintenance, cleaning) 33%
- Air traffic control & airport 9%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Fort Lauderdale (FLL) to Chicago (MDW)
Only 5 flights on record, which is too few for reliable odds.
- On-time arrivals
- 50.0%
- Less than 15 minutes late
- Cancelled
- 20.0%
- Of scheduled flights
- Average delay when late
- 63 min
- Flights arriving 15+ minutes late
- Flights tracked
- 5
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 79%
- Airline (crew, maintenance, cleaning) 17%
- Air traffic control & airport 5%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Baltimore (BWI) to Greenville/Greer/Spartanburg (GSP)
Only 4 flights on record, which is too few for reliable odds.
- On-time arrivals
- 100.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- —
- Flights arriving 15+ minutes late
- Flights tracked
- 4
- Scheduled flights in the period
Greenville/Greer/Spartanburg (GSP) to Nashville (BNA)
Only 4 flights on record, which is too few for reliable odds.
- On-time arrivals
- 100.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- —
- Flights arriving 15+ minutes late
- Flights tracked
- 4
- Scheduled flights in the period
Miami (MIA) to Austin (AUS)
Only 3 flights on record, which is too few for reliable odds.
- On-time arrivals
- 100.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- —
- Flights arriving 15+ minutes late
- Flights tracked
- 3
- Scheduled flights in the period
Spokane (GEG) to Sacramento (SMF)
Only 1 flight on record, which is too few for reliable odds.
- On-time arrivals
- 0.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 146 min
- Flights arriving 15+ minutes late
- Flights tracked
- 1
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 100%
- Late-arriving aircraft 0%
- Air traffic control & airport 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Show as table
| Month | On time | Flights |
|---|---|---|
| November 2025 | 85.2% | 29 |
| December 2025 | 75.9% | 31 |
| January 2026 | 80.0% | 5 |
| February 2026 | 91.7% | 13 |
| March 2026 | 60.0% | 5 |
| April 2026 | 100.0% | 1 |
| June 2026 | 61.5% | 27 |
| July 2026 | 46.4% | 30 |
| August 2026 | 82.6% | 23 |
Source: U.S. DOT Bureau of Transportation Statistics on-time data, September 2025 – August 2026. Covers flights operated by reporting U.S. carriers. About our data