Route reliability record
BWI→PHX
Baltimore to Phoenix
- Flights
- 1,287
- Period
- July 2025 to June 2026
- Distance
- 1,999 mi
- Carriers
- 1
This route lands a B, 2 points worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about 50 minutes on average. That is a workable record, not a spotless one. That rests on 1,287 BWI to PHX flights, with a median arrival 4 minutes early.
Best time to fly BWI to PHX: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 89.0% of the time and Tuesday flights 79.5%, against 76.0% 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
76.0%
Arrivals under 15 minutes late, of 1,271 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
1.09%
National rate is 1.81%
Best carrier
Southwest
76.0% on time across 1,287 flights
These figures cover 1,287 flights between July 2025 and June 2026. The median arrival is 4 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
Which airline is most reliable on BWI to PHX
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 |
|---|---|---|---|---|---|
| Southwest Airlines | 1,287 | 76.0% | 50 min | 1.09% | B |
Best ways to make this trip
The most reliable ways to fly Baltimore to Phoenix
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 2 of the top 3 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. IAD → PHXWashington to Phoenix | United Airlines | 84.2% | 84.9% | 0.79% | 8am–11am, Tue | UA 1938 17:26 |
| 2. DCA → PHXWashington to Phoenix | American Airlines | 81.1% | 82.3% | 1.47% | 5am–8am, Tue | AA 1218 10:05 |
| 3. BWI → PHXBaltimore to Phoenix | Southwest Airlines | 75.2% | 76.0% | 1.09% | 5am–8am, Tue | — |
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 28 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–8am301 flights89.0%
- 8am–11am240 flights84.4%
- 11am–2pm103 flights84.3%
- 2pm–5pm211 flights67.9%
- 5pm–8pm223 flights66.7%
- 8pm–5am209 flights61.3%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 61.3% on time, against 89.0% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 301 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 26 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.
June is the worst month at 62.1% on time, 26 points below January, the best at 88.2%. 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. May was the busiest month here, with 123 flights.
Across the week, Tuesday is the strongest day at 79.5% on time and Sunday the weakest at 68.3%. 11 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 15,000 reported delay minutes.
- 41%Late-arriving aircraft
- 38%Carrier
- 18%National Airspace System
- 2%Extreme weather
- 1%Security
41% 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 15,000 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 15,282 reported delay minutes.
The largest share of delay minutes, 38%, 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 5,864 of the 15,000 delay minutes reported here.
Cancellations sit at 1.09% against a national 1.81%, which is ordinary. Diversions add another 0.16%.
Connections and stage length
What a delay here actually costs
6.2% 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 about 50 minutes, which a normal layover absorbs.
At 1,999 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 80.3% on time across 1,289 flights, 4 points above 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 4 points of difference.
The sample behind these figures is 1,287 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 PHX 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. January runs 88.2% on time and June 62.1%, a swing of 26 points. If the dates move at all, move them out of June before you think about anything else. 1,271 completed flights over 12 months sit behind that.
Common questions
BWI to PHX questions
How often is BWI to PHX 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 24.0% of the 1,287 flights in this analysis, against 22.4% nationally. Delayed flights are late by about 50 minutes on average.
How reliable is BWI to PHX compared with the rest of the country?
76.0% of flights arrive on time here against a national 77.6%, a difference of 2 points against it. That is worth a B on this site's grading scale.
What time of day has the fewest delays on BWI to PHX?
The 5am–8am departure window is the strongest at 89.0% on time. The 8pm–5am window is the weakest at 61.3%, 28 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 June delays on BWI to PHX?
June is the weakest month at 62.1% on time, compared with 88.2% in January. Across the year that is 26 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
- PHX to BWI — the return legseparate record
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- Phoenix Sky Harbor International (PHX) delay statistics
- BWI to ATL, a related route80.6%
- DEN to PHX, a related route75.7%
- BWI to MCO, a related route75.6%
- Southwest Airlines on-time record76.0%
- 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. BWI to PHX and PHX to BWI 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.