Route reliability record
PHX→BOS
Phoenix to Boston
- Flights
- 2,022
- Period
- July 2025 to June 2026
- Distance
- 2,300 mi
- Carriers
- 3
This route lands a B, level with the national rate of 77.6%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 2,022 PHX to BOS flights, of which American Airlines flew 1,314 at 78.5% on time.
Best time to fly PHX to BOS: a 8pm–5am departure, ideally on a Saturday. Flights in that window arrived on time 81.0% of the time and Saturday flights 82.5%, against 77.3% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.3%
Arrivals under 15 minutes late, of 1,982 completed flights
Avg delay
79 min
Across delayed arrivals only, not all flights
Cancelled
1.83%
National rate is 1.81%
Best carrier
American
78.5% on time across 1,314 flights
These figures cover 2,022 flights between July 2025 and June 2026. Beyond the headline rate, 8.7% 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 PHX to BOS
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 |
|---|---|---|---|---|---|
| American Airlines | 1,314 | 78.5% | 70 min | 1.60% | B |
| Delta Air Lines | 428 | 77.3% | 106 min | 2.34% | B |
| JetBlue Airwaysthin sample | 280 | 71.4% | 79 min | 2.14% | C |
No carrier stands out. American tops the table at 78.5%, about a point clear of the bottom, which is inside the range this kind of sample moves year to year.
Best ways to make this trip
The most reliable ways to fly Phoenix to Boston
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. PHX → BOSPhoenix to Boston | American Airlines | 77.2% | 78.5% | 1.60% | 8pm–5am, Sat | — |
| 2. PHX → BOSPhoenix to Boston | Delta Air Lines | 75.5% | 77.3% | 2.34% | 8pm–5am, Sat | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 2,022 flights.
- 5am–8am—
- 8am–11am364 flights80.8%
- 11am–2pm565 flights72.4%
- 2pm–5pm397 flights74.4%
- 5pm–8pm2 flights—
- 8pm–5am694 flights81.0%
Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 72.4% on time against 81.0% for 8pm–5am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8pm–5am window is the busiest, with 694 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 22 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.
Delays peak in October, when the on-time rate falls to 63.9%. August is the strongest month at 85.4%. Moving a flexible trip across that boundary buys 22 points. April was the busiest month here, with 211 flights.
Across the week, Saturday is the strongest day at 82.5% on time and Thursday the weakest at 70.7%. 12 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 36,000 reported delay minutes.
- 42%Late-arriving aircraft
- 34%Carrier
- 22%National Airspace System
- 2%Extreme weather
42% 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 36,000 reported delay minutes here, that single category outweighs weather by 27 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 35,504 reported delay minutes.
The largest share of delay minutes, 34%, 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 12,000 of the 36,000 delay minutes reported here.
Cancellations sit at 1.83% against a national 1.81%, which is ordinary. Diversions add another 0.15%.
Connections and stage length
What a delay here actually costs
8.7% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
At 2,300 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 runs 76.7% on time across 2,024 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 2,022 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 BOS 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. August runs 85.4% on time and October 63.9%, a swing of 22 points. If the dates move at all, move them out of October before you think about anything else. 1,982 completed flights over 12 months sit behind that.
Common questions
PHX to BOS questions
How often is PHX to BOS 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 22.7% of the 2,022 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on PHX to BOS?
American Airlines leads at 78.5% on time across 1,314 flights. Delta Air Lines is at the other end on 77.3%, a gap of about a point. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on PHX to BOS?
The 8pm–5am departure window is the strongest at 81.0% on time. The 11am–2pm window is the weakest at 72.4%, 9 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 October delays on PHX to BOS?
October is the weakest month at 63.9% on time, compared with 85.4% in August. Across the year that is 22 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
- BOS to PHX — the return legseparate record
- Phoenix Sky Harbor International (PHX) delay statistics
- Boston Logan International (BOS) delay statistics
- American Airlines on PHX to BOS78.5%
- Delta Air Lines on PHX to BOS77.3%
- JetBlue Airways on PHX to BOS71.4%
- PHX to DEN, a related route77.2%
- DCA to BOS, a related route71.4%
- PHX to LAX, a related route82.8%
- American Airlines on-time record78.5%
- Delta Air Lines on-time record77.3%
- JetBlue Airways on-time record71.4%
- 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. PHX to BOS and BOS to PHX 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.