Flight WN4129
Southwest Airlines flight WN4129
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Alerts at this flight's airports
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Watch Ground Delay Program SAN
Ground Delay Program at San Diego International Airport (SAN): Average 37 minutes, up to 1 hour and 11 minutes
Reason: airport volume
Airport status
-
Advisory Coastal Flood Statement FLL
COASTAL FLOOD STATEMENT NOW IN EFFECT THROUGH THURSDAY EVENING
Weather
San Diego (SAN) to Sacramento (SMF)
Historically, this flight arrives 15+ minutes late 20% of the time, and when it is late the delay averages 56 minutes. It was cancelled 0.0% of the time.
- On-time arrivals
- 80.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 56 min
- Flights arriving 15+ minutes late
- Flights tracked
- 50
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 89%
- Airline (crew, maintenance, cleaning) 7%
- Air traffic control & airport 4%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Dallas (DAL) to Phoenix (PHX)
Historically, this flight arrives 15+ minutes late 51% of the time, and when it is late the delay averages 57 minutes. It was cancelled 0.0% of the time.
- On-time arrivals
- 48.8%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 57 min
- Flights arriving 15+ minutes late
- Flights tracked
- 43
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 52%
- Airline (crew, maintenance, cleaning) 42%
- Air traffic control & airport 5%
- Extreme weather 1%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Ontario (ONT) to Denver (DEN)
Historically, this flight arrives 15+ minutes late 12% of the time, and when it is late the delay averages 35 minutes. It was cancelled 0.0% of the time.
- On-time arrivals
- 87.9%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 35 min
- Flights arriving 15+ minutes late
- Flights tracked
- 33
- Scheduled flights in the period
What caused the delays
- Air traffic control & airport 85%
- Airline (crew, maintenance, cleaning) 15%
- Late-arriving aircraft 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Pittsburgh (PIT) to Houston (HOU)
Historically, this flight arrives 15+ minutes late 4% of the time, and when it is late the delay averages 62 minutes. It was cancelled 0.0% of the time.
- On-time arrivals
- 96.3%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 62 min
- Flights arriving 15+ minutes late
- Flights tracked
- 27
- 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).
Las Vegas (LAS) to Tampa (TPA)
Only 13 flights on record, which is too few for reliable odds.
- On-time arrivals
- 84.6%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 41 min
- Flights arriving 15+ minutes late
- Flights tracked
- 13
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 45%
- Extreme weather 39%
- Late-arriving aircraft 8%
- Air traffic control & airport 8%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
St Louis (STL) to Sarasota/Bradenton (SRQ)
Only 8 flights on record, which is too few for reliable odds.
- On-time arrivals
- 37.5%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 35 min
- Flights arriving 15+ minutes late
- Flights tracked
- 8
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 89%
- Airline (crew, maintenance, cleaning) 10%
- Air traffic control & airport 2%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Las Vegas (LAS) to Dallas (DAL)
Only 7 flights on record, which is too few for reliable odds.
- On-time arrivals
- 16.7%
- Less than 15 minutes late
- Cancelled
- 14.3%
- Of scheduled flights
- Average delay when late
- 57 min
- Flights arriving 15+ minutes late
- Flights tracked
- 7
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 55%
- Airline (crew, maintenance, cleaning) 27%
- Air traffic control & airport 18%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Washington (DCA) to Chicago (MDW)
Only 6 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
- 239 min
- Flights arriving 15+ minutes late
- Flights tracked
- 6
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 84%
- Air traffic control & airport 16%
- Late-arriving aircraft 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Indianapolis (IND) to Fort Lauderdale (FLL)
Only 5 flights on record, which is too few for reliable odds.
- On-time arrivals
- 40.0%
- Less than 15 minutes late
- Cancelled
- 0.0%
- Of scheduled flights
- Average delay when late
- 39 min
- Flights arriving 15+ minutes late
- Flights tracked
- 5
- Scheduled flights in the period
What caused the delays
- Late-arriving aircraft 59%
- Air traffic control & airport 32%
- Airline (crew, maintenance, cleaning) 9%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Fort Lauderdale (FLL) to Pittsburgh (PIT)
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
- 26 min
- Flights arriving 15+ minutes late
- Flights tracked
- 1
- Scheduled flights in the period
What caused the delays
- Airline (crew, maintenance, cleaning) 81%
- Air traffic control & airport 19%
- Late-arriving aircraft 0%
- Extreme weather 0%
- Security 0%
Share of delay minutes airlines attributed to each cause (BTS).
Oakland (OAK) to Albuquerque (ABQ)
Only 1 flight 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
- 1
- Scheduled flights in the period
Phoenix (PHX) to Denver (DEN)
Only 1 flight 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
- 1
- Scheduled flights in the period
Sacramento (SMF) to Phoenix (PHX)
Only 1 flight 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
- 1
- Scheduled flights in the period
Show as table
| Month | On time | Flights |
|---|---|---|
| September 2025 | 96.2% | 26 |
| October 2025 | 100.0% | 1 |
| November 2025 | 100.0% | 5 |
| December 2025 | 58.3% | 12 |
| January 2026 | 75.0% | 4 |
| February 2026 | 100.0% | 1 |
| March 2026 | 88.9% | 27 |
| April 2026 | 76.7% | 30 |
| May 2026 | 69.0% | 30 |
| June 2026 | 42.3% | 26 |
| July 2026 | 57.7% | 26 |
| August 2026 | 75.0% | 8 |
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