Route profile
MIA→IAD
Flight reliability, delays and best times to fly from Miami to Washington, 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 62% of comparable major US routes (4,598 compared)
Calculated from 1,745 flights. How this is calculated
MIA → IAD arrives on time 82.5% of the time; the return trip, IAD → MIA, arrives on time 81.4% of the time.
MIA → IAD spends 29.5 minutes on the ground on a 921-mile trip: 21.6 minutes from pushback to wheels-up at MIA and 7.9 minutes from touchdown to gate at IAD.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
Which day you fly matters unusually much here, a wider weekday spread than 91% of 4,467 comparable routes.
88.7% on time on a typical Wednesday, against 74.8% on a Sunday.
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 4,467 in the comparison.
What sets this route apart
Where MIA to IAD differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
MIA to IAD is at its best against routes of similar length for flights scheduled at 1 PM: 83.6% arrive on time, 6.9 points ahead of the 76.7% those routes manage at that hour. Against all other routes the gap is 6.5 points.
MIA to IAD holds up on Wednesdays better than routes of similar length do: 88.7% on time to their 80.2%, a 8.5 points lead. Against all other routes the gap is 7.9 points.
May is kinder to MIA to IAD than to routes of similar length: 91.4% on time against 74.4%, 17 points better. Against all other routes the gap is 16.2 points.
United Airlines does better on MIA to IAD than on its routes of similar length: 83.8% on time here, 80.6% there, 3.2 points apart. Against all other routes the gap is 3.9 points.
MIA to IAD against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 1 PM departures | 83.6% | routes of similar length | 76.7% | +6.9 pts | 1,001 here, 166,851 there |
| Weekday: Wednesday | 88.7% | routes of similar length | 80.2% | +8.5 pts | 222 here, 386,807 there |
| Month: May | 91.4% | routes of similar length | 74.4% | +17.0 pts | 140 here, 238,045 there |
| Airline: United Airlines | 83.8% | routes of similar length | 80.6% | +3.2 pts | 1,560 here, 453,465 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
37 min late
against a median of 9 min early
Percentiles over 1,745 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at IAD after arriving from MIA.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 29% | High risk |
| 45 min | 17% | High risk |
| 60 min | 11% | Some risk |
| 90 min | 6.7% | Some risk |
| 120 min | 4.6% | 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 0.29% of the time, which a late arrival never shows up in.
Chance of missing is the share of 1,722 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 37 minutes late (90th-percentile gate arrival delay), over 1,745 operations.
Any other layover length: connection checker.
Best time to fly
MIA → IAD flights departing 5–9 AM arrived on time 86.1% of the time, against 75.3% for 6–9 PM departures, a gap of 10.8 percentage points.
By departure window
By departure hour
- 12 AM to 7 AM: too few flights to score
- 8 AM: 85.9% on time from 278 flights
- 9 AM to 11 AM: too few flights to score
- 12 PM: 81.4% on time from 140 flights
- 1 PM: 83.6% on time from 1,016 flights
- 2 PM to 5 PM: too few flights to score
- 6 PM: 75.3% on time from 162 flights
- 7 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why MIA → IAD 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 MIA → IAD. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on MIA → IAD, at 36.9%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 86.1% of the time and 6–9 PM departures 75.3%.
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 | 1,579 | 83.8% | 0.89% | -10 min | 6.3% |
Other ways to fly Miami to Washington
Airport pairs in the same two city markets, as the DOT defines them.
MIA → IAD is the most reliable pairing for this journey at 82.5% on time, against 74.5% for MIA → DCA.
Flying to IAD from the Miami area? Compare MIA, FLL for IAD, with the same test for what counts as a real difference.
Weekly and seasonal patterns
By day of week
Wednesday is historically the most reliable day and Sunday the least, a gap of 13.9 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 83.1% against 81.6% in the 12 months before — improving by 1.5 percentage points.
Data and methodology
Calculated by FlyerIntel from 1,745 MIA → 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