Route profile
IAD→PHX
Flight reliability, delays and best times to fly from Washington to Phoenix, 1,956 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 72% of comparable major US routes (4,598 compared)
Calculated from 3,101 flights. How this is calculated
IAD → PHX arrives on time 81.5% of the time; the return trip, PHX → IAD, arrives on time 85.7% of the time, a 4.2-point gap between the two directions of the same city pair.
IAD → PHX spends 26.2 minutes on the ground on a 1,956-mile trip: 20.5 minutes from pushback to wheels-up at IAD and 5.6 minutes from touchdown to gate at PHX.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
This route has stayed remarkably steady year over year, a smaller swing than 97% of 5,368 comparable routes.
81.8% on time over the most recent 12 months (2025-08 to 2026-07), against 82.0% in the 12 months before (2024-08 to 2025-07), virtually unchanged.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 5,368 in the comparison.
What sets this route apart
Where IAD to PHX differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
IAD to PHX is at its best against routes of similar length for flights scheduled at 12 PM: 89.1% arrive on time, 11.9 points ahead of the 77.2% those routes manage at that hour. Against all other routes the gap is 9.7 points.
IAD to PHX holds up on Sundays better than routes of similar length do: 81.7% on time to their 75.7%, a 6 points lead. Against all other routes the gap is 6.9 points.
March is kinder to IAD to PHX than to routes of similar length: 87.7% on time against 78.8%, 8.9 points better. Against all other routes the gap is 9.8 points.
In July, IAD to PHX runs 7.8 points below routes of similar length, 62.5% on time to 70.3%. Against all other routes the gap is 7.2 points.
United Airlines does better on IAD to PHX than on its routes of similar length: 84.9% on time here, 80.8% there, 4.1 points apart. Against all other routes the gap is 5 points.
IAD to PHX against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 12 PM departures | 89.1% | routes of similar length | 77.2% | +11.9 pts | 442 here, 55,251 there |
| Weekday: Sunday | 81.7% | routes of similar length | 75.7% | +6.0 pts | 449 here, 163,057 there |
| Month: March | 87.7% | routes of similar length | 78.8% | +8.9 pts | 326 here, 89,474 there |
| Month: July | 62.5% | routes of similar length | 70.3% | −7.8 pts | 240 here, 133,921 there |
| Airline: United Airlines | 84.9% | routes of similar length | 80.8% | +4.1 pts | 2,305 here, 201,609 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 1,956 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
When it goes wrong
July 2023 – July 2026
35 min late
against a median of 8 min early
Percentiles over 3,101 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at PHX after arriving from IAD.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 34% | Likely to miss |
| 45 min | 18% | High risk |
| 60 min | 11% | Some risk |
| 90 min | 5.7% | Some risk |
| 120 min | 3.8% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.97% of the time and diverts 0.19% of the time, which a late arrival never shows up in.
Chance of missing is the share of 3,065 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 35 minutes late (90th-percentile gate arrival delay), over 3,101 operations.
Any other layover length: connection checker.
Best time to fly
IAD → PHX flights departing 5–9 AM arrived on time 92.7% of the time, against 74.9% for 3–6 PM departures, a gap of 17.8 percentage points.
By departure window
By departure hour
- 12 AM to 7 AM: too few flights to score
- 8 AM: 92.7% on time from 733 flights
- 9 AM to 11 AM: too few flights to score
- 12 PM: 89.1% on time from 446 flights
- 1 PM to 2 PM: too few flights to score
- 3 PM: 81.9% on time from 144 flights
- 4 PM: 75.8% on time from 244 flights
- 5 PM: 74.0% on time from 1,287 flights
- 6 PM: 75.8% on time from 125 flights
- 7 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why IAD → PHX runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for IAD → PHX. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on IAD → PHX, at 38.2%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 92.7% of the time and 3–6 PM departures 74.9%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| United Airlines | 2,334 | 84.9% | 1.11% | -11 min | 5.4% |
| Southwest Airlines | 767 | 71.3% | 0.52% | 1 min | 7.1% |
United Airlines flew 75.3% of the 3,101 flights listed.
United Airlines arrived on time 13.6 percentage points more often than Southwest Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
| Flight | Scheduled | Operations | On time |
|---|---|---|---|
| UA1938 United Airlines | 5:50 PM | 983 | 77.5% |
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Friday the least, a gap of 5.5 percentage points.
By month
- Jan: 81.0%
- Feb: 87.2%
- Mar: 87.7%
- Apr: 84.5%
- May: 82.2%
- Jun: 70.4%
- Jul: 62.5%
- Aug: 79.4%
- Sep: 80.7%
- Oct: 84.6%
- Nov: 84.6%
- Dec: 87.2%
July is historically the weakest month and March the strongest, a spread of 25.2 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: too few flights to score (31)
- August 2023: too few flights to score (31)
- September 2023: too few flights to score (31)
- October 2023: too few flights to score (59)
- November 2023: too few flights to score (51)
- December 2023: too few flights to score (56)
- January 2024: too few flights to score (39)
- February 2024: too few flights to score (44)
- March 2024: too few flights to score (87)
- April 2024: too few flights to score (105)
- May 2024: too few flights to score (106)
- June 2024: too few flights to score (90)
- July 2024: too few flights to score (93)
- August 2024: too few flights to score (93)
- September 2024: too few flights to score (90)
- October 2024: too few flights to score (98)
- November 2024: too few flights to score (117)
- December 2024: 87.9% from 124 flights
- January 2025: too few flights to score (87)
- February 2025: too few flights to score (94)
- March 2025: 90.2% from 124 flights
- April 2025: 79.2% from 120 flights
- May 2025: too few flights to score (113)
- June 2025: too few flights to score (90)
- July 2025: too few flights to score (92)
- August 2025: too few flights to score (88)
- September 2025: too few flights to score (87)
- October 2025: too few flights to score (97)
- November 2025: too few flights to score (109)
- December 2025: too few flights to score (108)
- January 2026: too few flights to score (98)
- February 2026: too few flights to score (81)
- March 2026: too few flights to score (117)
- April 2026: too few flights to score (91)
- May 2026: too few flights to score (96)
- June 2026: too few flights to score (33)
- July 2026: too few flights to score (31)
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 81.8% against 82.0% in the 12 months before — broadly unchanged.
Data and methodology
Calculated by FlyerIntel from 3,101 IAD → PHX flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed