Route reliability record
BOS→AUS
Boston to Austin
- Flights
- 1,634
- Period
- July 2025 to June 2026
- Distance
- 1,698 mi
- Carriers
- 3
This route sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 1,634 BOS to AUS flights, with a median arrival 6 minutes early.
Best time to fly BOS to AUS: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 84.6% of the time and Wednesday flights 74.6%, against 72.2% for the route overall.
The national on-time rate over the same period is 77.6%, so this route runs 5 points behind the country as a whole. Across a thousand flights that is about 54 extra late arrivals.
Key figures
On time
72.2%
Arrivals under 15 minutes late, of 1,597 completed flights
Avg delay
77 min
Across delayed arrivals only, not all flights
Cancelled
1.96%
National rate is 1.81%
Best carrier
Delta
74.9% on time across 988 flights
These figures cover 1,634 flights between July 2025 and June 2026. Beyond the headline rate, 11.1% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on BOS to AUS
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 988 | 74.9% | 93 min | 2.63% | C |
| JetBlue Airwaysthin sample | 364 | 72.5% | 61 min | 1.10% | C |
| Southwest Airlinesthin sample | 282 | 62.5% | 54 min | 0.71% | D+ |
Flight by flight
Flights on BOS to AUS
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 26 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am429 flights84.6%
- 8am–11am164 flights83.4%
- 11am–2pm468 flights72.6%
- 2pm–5pm244 flights58.3%
- 5pm–8pm327 flights59.7%
- 8pm–5am2 flights—
Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 84.6% of the time, against 58.3% for the afternoon window. That is 26 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 468 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 16 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
April is the best month on the calendar at 81.2% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. June was the busiest month here, with 162 flights.
Across the week, Wednesday is the strongest day at 74.6% on time and Sunday the weakest at 66.1%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 34,000 reported delay minutes.
- 41%Carrier
- 34%Late-arriving aircraft
- 23%National Airspace System
- 2%Extreme weather
- 0%Security
34% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 34,000 reported delay minutes here, that single category outweighs weather by 18 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 34,044 reported delay minutes.
The largest share of delay minutes, 41%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 14,000 of the 34,000 delay minutes reported here.
Cancellations sit at 1.96% against a national 1.81%, which is ordinary. Diversions add another 0.31%.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.1% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum 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 65.4% on time across 1,634 flights, 7 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 7 points of difference.
The sample behind these figures is 1,634 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in AUS after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 81.2% on time and September 65.4%, a swing of 16 points. If the dates move at all, move them out of September before you think about anything else. 1,597 completed flights over 12 months sit behind that.
Common questions
BOS to AUS questions
How often is BOS to AUS delayed?
Roughly one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 27.8% of the 1,634 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is BOS to AUS compared with the rest of the country?
72.2% of flights arrive on time here against a national 77.6%, a difference of 5 points against it. That is worth a C on this site's grading scale.
What time of day has the fewest delays on BOS to AUS?
The 5am–8am departure window is the strongest at 84.6% on time. The 2pm–5pm window is the weakest at 58.3%, 26 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are September delays on BOS to AUS?
September is the weakest month at 65.4% on time, compared with 81.2% in April. Across the year that is 16 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- AUS to BOS — the return legseparate record
- Boston Logan International (BOS) delay statistics
- Austin-Bergstrom International (AUS) delay statistics
- Delta Air Lines on BOS to AUS74.9%
- JetBlue Airways on BOS to AUS72.5%
- Southwest Airlines on BOS to AUS62.5%
- BOS to DCA, a related route74.0%
- DEN to AUS, a related route76.1%
- BOS to ORD, a related route72.7%
- Delta Air Lines on-time record74.9%
- JetBlue Airways on-time record72.5%
- Southwest Airlines on-time record62.5%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. BOS to AUS and AUS to BOS are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.