Carrier route record
WNBOS→AUS
Southwest Airlines · Boston to Austin
- Flights
- 286
- Period
- September 2025 to August 2026
- Share of route
- 17%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on BOS to AUS draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 50 minutes behind schedule. Build slack into anything you connect to. That rests on 286 flights. The strongest carrier on the route with a full sample, JetBlue Airways, flew 426 at 74.9% on time.
The national on-time rate over the same period is 77.3%, so Southwest on BOS to AUS runs 12 points behind the country as a whole. Across a thousand flights that is about 117 extra late arrivals.
Key figures
On time
65.6%
Arrivals under 15 minutes late, of 282 completed flights
Avg delay
52 min
Across delayed arrivals only, not all flights
Cancelled
1.40%
National rate is 1.89%
Whole route
72.6%
Every carrier on BOS to AUS, 1,713 flights
These figures cover 286 flights between September 2025 and August 2026. Beyond the headline rate, 11.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Southwest against every carrier on BOS to AUS
Southwest flew 286 of the 1,713 flights on BOS to AUS, about 17% of it. Its 65.6% on time is 7 points worse than the route as a whole, which runs 72.6%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from JetBlue at 74.9% to Southwest at 65.6%.
The two carriers here are closely matched: about a point separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| JetBlue Airways | 426 | 74.9% | 61 min | 2.58% | C |
| Delta Air Lines | 1,001 | 73.7% | 87 min | 2.60% | C |
| Southwest Airlines (this page)thin sample | 286 | 65.6% | 52 min | 1.40% | C |
No carrier stands out. JetBlue tops the table at 74.9%, about a point clear of the bottom, which is inside the range this kind of sample moves year to year.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 34 points, against about a point between the best and worst carrier.
- 5am–8am—
- 8am–11am77 flights81.8%
- 11am–2pm97 flights74.7%
- 2pm–5pm108 flights48.1%
- 5pm–8pm4 flights—
- 8pm–5am—
Scale runs 40% to 85%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 81.8% of the time, against 48.1% for the afternoon window. That is 34 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 108 flights scheduled in it.
Across the year
Southwest on BOS to AUS through the year
- Jul–Sep 202526 flights—
- Oct–Dec 202564 flights54.7%
- Jan–Mar 202652 flights80.0%
- Apr–Jun 202682 flights72.0%
- Jul–Sep 202662 flights75.0%
Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 65.6% on time across 286 flights.
Southwest on BOS to AUS did not run the same all year. Its best quarter was Jan–Mar 2026 at 80.0% on time and its weakest Oct–Dec 2025 at 54.7%, a swing of 25 points on roughly 72 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
Across the week, Friday is the strongest day at 83.3% on time and Tuesday the weakest at 51.4%, a spread of 32 points.
Arrival by arrival
How late Southwest on BOS to AUS runs when it is late
Southwest on BOS to AUS often beats the schedule: 71 of 282 completed flights, 25%, arrived 15 minutes or more early. The 97 late arrivals split 26 under half an hour, 39 between 30 and 60 minutes, and 32 an hour or more.
- 15+ min early71 flights25.2%
- Within 15 min114 flights40.4%
- 15–29 min late26 flights9.2%
- 30–59 min late39 flights13.8%
- 1–2 hours late27 flights9.6%
- 2+ hours late5 flights1.8%
Scale runs 0% to 100%.
Share of 282 completed flights by arrival against schedule.
A late pushback is often recovered here: of 126 departures that left 15 minutes late or more, 43 still arrived on time. 14 flights left on time and still arrived late.
The worst days
Worst days for Southwest on BOS to AUS
The latest arrival of the period was on 13 October 2025, 2 hours 43 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The five worst days are spread across October, July, May and March, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 October 2025 | 2 hours 43 minutes | Late-arriving aircraft |
| 28 July 2026 | 2 hours 41 minutes | Carrier |
| 26 October 2025 | 2 hours 28 minutes | Late-arriving aircraft |
| 4 May 2026 | 2 hours 25 minutes | Carrier |
| 15 March 2026 | 2 hours 19 minutes | National Airspace System |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 50% of the 5,029 delay minutes carriers reported here, and the remaining four split what is left.
- 50%Late-arriving aircraft
- 31%Carrier
- 17%National Airspace System
- 1%Extreme weather
50% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 5,029 reported delay minutes here, that single category outweighs weather by 35 to one. The split is drawn from 5,029 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 81.8% on time here.
Cancellations sit at 1.40% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
11.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 1,698 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 54.8% on time across 286 flights, 11 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 11 points of difference.
One caution: this is a thin sample. 286 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Southwest on BOS to AUS
Put together: treat all of this as provisional. 286 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 65.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 282 completed flights over 12 months sit behind that.
Related
Where to go next
- BOS to AUS, every carrier
- Southwest on AUS to BOS, the return leg
- JetBlue Airways on BOS to AUS74.9%
- Delta Air Lines on BOS to AUS73.7%
- Southwest Airlines network-wide record
- Boston Logan International (BOS) delay statistics
- Austin-Bergstrom International (AUS) delay statistics
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.