Route reliability record
PHX→BOS
Phoenix to Boston
- Flights
- 2,010
- Period
- September 2025 to August 2026
- Distance
- 2,300 mi
- Carriers
- 3
This route sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.3%. The late ones land a little over an hour behind schedule. That rests on 2,010 PHX to BOS flights, of which Delta Air Lines flew 429 at 76.6% on time.
Best time to fly PHX to BOS: a 8pm–5am departure, ideally on a Monday. Flights in that window arrived on time 80.8% of the time and Monday flights 80.4%, against 75.7% for the route overall.
The US average over the same twelve months is 77.3%, 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
75.7%
Arrivals under 15 minutes late, of 1,969 completed flights
Avg delay
74 min
Across delayed arrivals only, not all flights
Cancelled
1.84%
National rate is 1.89%
Best carrier
Delta
76.6% on time across 429 flights
These figures cover 2,010 flights between September 2025 and August 2026. Beyond the headline rate, 9.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on PHX to BOS
The two carriers here are closely matched: half 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 |
|---|---|---|---|---|---|
| Delta Air Lines | 429 | 76.6% | 84 min | 2.33% | B |
| American Airlines | 1,308 | 76.1% | 69 min | 1.61% | B |
| JetBlue Airwaysthin sample | 273 | 72.2% | 80 min | 2.20% | C |
No carrier stands out. Delta tops the table at 76.6%, half a point clear of the bottom, which is inside the range this kind of sample moves year to year.
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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 | 74.9% | 76.1% | 1.61% | 8pm–5am, Sat | — |
| 2. PHX → BOSPhoenix to Boston | Delta Air Lines | 74.8% | 76.6% | 2.33% | 8pm–5am, Mon | — |
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 matters more here than the choice of carrier. The gap between the best and worst window is 12 points, against half a point between the best and worst carrier.
- 5am–8am—
- 8am–11am365 flights80.3%
- 11am–2pm566 flights69.2%
- 2pm–5pm396 flights71.8%
- 5pm–8pm2 flights—
- 8pm–5am681 flights80.8%
Scale runs 60% 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 69.2% on time against 80.8% 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 681 flights scheduled in it.
Explore
Filter PHX to BOS by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On PHX to BOS, the best departure window is 8pm–5am at 80.8% on time and the worst is 11am–2pm at 69.2%, a wide gap of 11.6 points. All US flights leaving 8pm–5am ran 70.1%.
- 5–8am—
- 8–11am80.3%
- 11am–2pm69.2%
- 2–5pm71.8%
- 5–8pm—
- 8pm–5am80.8%
best all US flightsScale 60% to 95%. Cells under 30 flights show a dash.
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.
July is the worst month at 62.0% on time, 22 points below May, the best at 83.5%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. April was the busiest month here, with 211 flights.
Across the week, Monday is the strongest day at 80.4% on time and Friday the weakest at 71.5%, a spread of 9 points.
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 35,000 reported delay minutes.
- 42%Late-arriving aircraft
- 31%Carrier
- 26%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. Across 35,000 reported delay minutes here, that single category outweighs weather by 21 to one. The split is drawn from 35,278 reported delay minutes.
Cancellations sit at 1.84% against a national 1.89%, which is ordinary. Diversions add another 0.20%.
Connections and stage length
What a delay here actually costs
9.3% 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 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 77.3% on time across 2,012 flights, within 2 points 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 2,010 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. May runs 83.5% on time and July 62.0%, a swing of 22 points. If the dates move at all, move them out of July before you think about anything else. 1,969 completed flights over 12 months sit behind that.
Common questions
PHX to BOS questions
How often is PHX to BOS delayed?
About 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 24.3% of the 2,010 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on PHX to BOS?
Delta Air Lines leads at 76.6% on time across 429 flights. American Airlines is at the other end on 76.1%, a gap of half 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 80.8% on time. The 11am–2pm window is the weakest at 69.2%, 12 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 July delays on PHX to BOS?
July is the weakest month at 62.0% on time, compared with 83.5% in May. 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
- Delta Air Lines on PHX to BOS76.6%
- American Airlines on PHX to BOS76.1%
- JetBlue Airways on PHX to BOS72.2%
- PHX to DEN, a related route76.7%
- DCA to BOS, a related route70.1%
- PHX to LAX, a related route82.1%
- Delta Air Lines on-time record76.6%
- American Airlines on-time record76.1%
- JetBlue Airways on-time record72.2%
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.