Route profile
SAN→IAD
Flight reliability, delays and best times to fly from San Diego to Washington, 2,253 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 85% of comparable major US routes (4,598 compared)
Calculated from 4,729 flights. How this is calculated · What counts as on time
SAN → IAD arrives on time 85.1% of the time; the return trip, IAD → SAN, arrives on time 83.2% of the time.
SAN → IAD spends 30.9 minutes on the ground on a 2,253-mile trip: 23.6 minutes from pushback to wheels-up at SAN and 7.3 minutes from touchdown to gate at IAD.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
Unlike most, it barely matters what time you fly this route, a steadier spread than 92% of 4,023 comparable routes.
88.2% on time for 9 PM–5 AM departures, against 79.7% for 9 AM–12 PM, a narrow gap either way.
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 4,023 in the comparison.
What sets this route apart
Where SAN to IAD differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
SAN to IAD is at its best against routes of similar length for flights scheduled at 1 PM: 92.1% arrive on time, 16.4 points ahead of the 75.7% those routes manage at that hour. Against all other routes the gap is 15 points.
SAN to IAD struggles most at 10 AM: 69.0% of its flights scheduled then arrive on time, 9.8 points behind the 78.8% on routes of similar length at the same hour. Against all other routes the gap is 13.7 points.
SAN to IAD holds up on Mondays better than routes of similar length do: 85.8% on time to their 78.4%, a 7.4 points lead. Against all other routes the gap is 8.6 points.
June is kinder to SAN to IAD than to routes of similar length: 85.4% on time against 74.4%, 11 points better. Against all other routes the gap is 12.7 points.
United Airlines does better on SAN to IAD than on its routes of similar length: 86.6% on time here, 81.2% there, 5.4 points apart. Against all other routes the gap is 6.7 points.
SAN to IAD against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 1 PM departures | 92.1% | routes of similar length | 75.7% | +16.4 pts | 343 here, 56,170 there |
| Hour: 10 AM departures | 69.0% | routes of similar length | 78.8% | −9.8 pts | 213 here, 58,834 there |
| Weekday: Monday | 85.8% | routes of similar length | 78.4% | +7.4 pts | 668 here, 175,328 there |
| Month: June | 85.4% | routes of similar length | 74.4% | +11.0 pts | 356 here, 106,215 there |
| Airline: United Airlines | 86.6% | routes of similar length | 81.2% | +5.4 pts | 3,549 here, 241,731 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 2,253 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.
Why SAN → IAD flights are cancelled
July 2023 – July 2026
SAN → IAD cancelled 57 of 4,729 scheduled flights — about 1 in every 83. The reason filed most often was the airline, 80.7% of the cancellations coded on this route — about 1 in every 103 scheduled flights.
Share of cancellations
Of 57 cancelled departures carrying a reason code.
What each reason means
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
46 cancellations, 80.7% of the total.
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
8 cancellations, 14.0% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
3 cancellations, 5.3% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. With only one or two carriers on the route, the split mostly reflects how they file. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
57 coded cancellations were recorded on SAN → IAD; the section appears from 50.
When it goes wrong
July 2023 – July 2026
25 min late
against a median of 10 min early
Percentiles over 4,729 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at IAD after arriving from SAN.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 29% | High risk |
| 45 min | 14% | Some risk |
| 60 min | 8.7% | Some risk |
| 90 min | 4.0% | Low risk |
| 120 min | 2.5% | 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 1.21% of the time and diverts 0.59% of the time, which a late arrival never shows up in.
Chance of missing is the share of 4,644 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 25 minutes late (90th-percentile gate arrival delay), over 4,729 operations.
Any other layover length: connection checker.
Best time to fly
SAN → IAD flights departing 9 PM–5 AM arrived on time 88.2% of the time, against 79.7% for 9 AM–12 PM departures, a gap of 8.5 percentage points.
By departure window
By departure hour
- 12 AM to 6 AM: too few flights to score
- 7 AM: 91.2% on time from 378 flights
- 8 AM: 81.7% on time from 1,634 flights
- 9 AM: 87.2% on time from 292 flights
- 10 AM: 69.0% on time from 216 flights
- 11 AM: too few flights to score
- 12 PM: 85.2% on time from 770 flights
- 1 PM: 92.1% on time from 351 flights
- 2 PM to 8 PM: too few flights to score
- 9 PM: 88.1% on time from 932 flights
- 10 PM: 88.5% on time from 150 flights
- 11 PM: too few flights to score
Why SAN → IAD runs late
July 2023 – July 2026
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for SAN → IAD. Only delays of 15 minutes or more are attributed. What the five causes mean
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 | 3,610 | 86.6% | 1.11% | -11 min | 3.9% |
| Alaska Airlines | 1,119 | 80.2% | 1.52% | -8 min | 4.7% |
United Airlines flew 76.3% of the 4,729 flights listed.
United Airlines arrived on time 6.4 percentage points more often than Alaska 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 |
|---|---|---|---|
| UA2129 United Airlines | 9:30 PM | 1,016 | 88.2% |
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Sunday the least, a gap of 6.0 percentage points.
By month
- Jan: 88.2%
- Feb: 90.8%
- Mar: 85.9%
- Apr: 86.0%
- May: 87.6%
- Jun: 85.4%
- Jul: 74.7%
- Aug: 81.5%
- Sep: 88.3%
- Oct: 84.6%
- Nov: 87.1%
- Dec: 85.1%
July is historically the weakest month and February the strongest, a spread of 16.1 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 78.3% from 154 flights
- August 2023: 82.1% from 155 flights
- September 2023: 89.9% from 150 flights
- October 2023: 87.7% from 154 flights
- November 2023: 85.7% from 140 flights
- December 2023: 87.6% from 138 flights
- January 2024: 88.2% from 143 flights
- February 2024: 89.9% from 143 flights
- March 2024: 90.3% from 155 flights
- April 2024: 84.7% from 150 flights
- May 2024: 91.0% from 146 flights
- June 2024: 85.0% from 120 flights
- July 2024: 71.7% from 124 flights
- August 2024: 77.7% from 124 flights
- September 2024: too few flights to score (119)
- October 2024: 71.0% from 124 flights
- November 2024: too few flights to score (118)
- December 2024: 77.4% from 124 flights
- January 2025: 87.6% from 124 flights
- February 2025: too few flights to score (112)
- March 2025: 85.4% from 124 flights
- April 2025: 79.7% from 120 flights
- May 2025: 81.5% from 124 flights
- June 2025: 78.4% from 120 flights
- July 2025: 78.3% from 122 flights
- August 2025: 84.4% from 124 flights
- September 2025: too few flights to score (119)
- October 2025: too few flights to score (119)
- November 2025: too few flights to score (115)
- December 2025: 90.2% from 122 flights
- January 2026: too few flights to score (112)
- February 2026: too few flights to score (100)
- March 2026: too few flights to score (116)
- April 2026: too few flights to score (111)
- May 2026: 89.9% from 120 flights
- June 2026: 92.5% from 120 flights
- July 2026: 69.4% from 124 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 88.2% against 81.2% in the 12 months before — improving by 7.0 percentage points.
Data and methodology
Calculated by FlyerIntel from 4,729 SAN → IAD 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