Route profile
IAD→MIA
Flight reliability, delays and best times to fly from Washington to Miami, 921 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 66% of comparable major US routes (4,598 compared)
Calculated from 1,744 flights. How this is calculated
IAD → MIA arrives on time 81.4% of the time; the return trip, MIA → IAD, arrives on time 82.5% of the time.
IAD → MIA spends 31.5 minutes on the ground on a 921-mile trip: 20.9 minutes from pushback to wheels-up at IAD and 10.6 minutes from touchdown to gate at MIA.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What sets this route apart
Where IAD to MIA differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
IAD to MIA holds up on Fridays better than routes of similar length do: 82.2% on time to their 75.9%, a 6.3 points lead. Against all other routes the gap is 6 points.
May is kinder to IAD to MIA than to routes of similar length: 85.5% on time against 74.4%, 11.1 points better. Against all other routes the gap is 10.3 points.
In January, IAD to MIA runs 7 points below routes of similar length, 71.4% on time to 78.4%. Against all other routes the gap is 7.7 points.
United Airlines does better on IAD to MIA than on its routes of similar length: 83.5% on time here, 80.6% there, 2.9 points apart. Against all other routes the gap is 3.6 points.
IAD to MIA against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Weekday: Friday | 82.2% | routes of similar length | 75.9% | +6.3 pts | 264 here, 422,499 there |
| Month: May | 85.5% | routes of similar length | 74.4% | +11.1 pts | 138 here, 238,047 there |
| Month: January | 71.4% | routes of similar length | 78.4% | −7.0 pts | 182 here, 212,942 there |
| Airline: United Airlines | 83.5% | routes of similar length | 80.6% | +2.9 pts | 1,563 here, 453,462 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 921 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
38 min late
against a median of 8 min early
Percentiles over 1,744 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at MIA after arriving from IAD.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 33% | Likely to miss |
| 45 min | 18% | High risk |
| 60 min | 11% | Some risk |
| 90 min | 6.3% | Some risk |
| 120 min | 4.1% | 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 1.03% of the time and diverts 0.06% of the time, which a late arrival never shows up in.
Chance of missing is the share of 1,725 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 38 minutes late (90th-percentile gate arrival delay), over 1,744 operations.
Any other layover length: connection checker.
Best time to fly
IAD → MIA flights departing 5–9 AM arrived on time 88.0% of the time, against 70.3% for 3–6 PM departures, a gap of 17.7 percentage points.
By departure window
By departure hour
- 12 AM to 7 AM: too few flights to score
- 8 AM: 88.0% on time from 529 flights
- 9 AM: 86.7% on time from 580 flights
- 10 AM to 12 PM: too few flights to score
- 1 PM: 82.7% on time from 140 flights
- 2 PM to 4 PM: too few flights to score
- 5 PM: 69.5% on time from 306 flights
- 6 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why IAD → MIA runs late
July 2023 – July 2026
airspace and airport capacity, including weather-driven flow control
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for IAD → MIA. Only delays of 15 minutes or more are attributed.
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 | 1,578 | 83.5% | 0.89% | -9 min | 5.5% |
Other ways to fly Washington to Miami
Airport pairs in the same two city markets, as the DOT defines them.
IAD → MIA is the most reliable pairing for this journey at 81.4% on time, against 77.2% for DCA → MIA.
Flying to MIA from the Washington area? Compare IAD, DCA, BWI for MIA, with the same test for what counts as a real difference.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
| Flight | Scheduled | Operations | On time |
|---|---|---|---|
| UA1073 United Airlines | 9:00 AM | 1,078 | 86.9% |
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Sunday the least, a gap of 7.7 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 83.2% against 81.3% in the 12 months before — improving by 1.9 percentage points.
Data and methodology
Calculated by FlyerIntel from 1,744 IAD → MIA 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