Carrier route record
UAIAD→FLL
United Airlines · Washington to Fort Lauderdale
- Flights
- 699
- Period
- September 2025 to August 2026
- Share of route
- 87%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on IAD to FLL lands a B+, 6 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 699 flights, with a median arrival 9 minutes early.
Set against the rest of the country, United's IAD to FLL record is 6 points better than the US average of 77.3%. That gap is worth roughly 62 fewer late arrivals for every thousand flights.
Key figures
On time
83.5%
Arrivals under 15 minutes late, of 693 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
0.57%
National rate is 1.89%
Whole route
79.0%
Every carrier on IAD to FLL, 802 flights
These figures cover 699 flights between September 2025 and August 2026. The median arrival is 9 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.
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Carrier by carrier
United against every carrier on IAD to FLL
United flew 699 of the 802 flights on IAD to FLL, most of the route. Its 83.5% on time is 5 points better than the route as a whole, which runs 79.0%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 83.5% to Frontier at 47.5%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
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 |
|---|---|---|---|---|---|
| United Airlines (this page) | 699 | 83.5% | 71 min | 0.57% | B+ |
| Frontier Airlinesthin sample | 103 | 47.5% | 95 min | 3.88% | F− |
Flight by flight
United flight numbers on IAD to FLL
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Departure window
When United runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 699 flights.
- 5am–8am—
- 8am–11am250 flights89.1%
- 11am–2pm142 flights82.1%
- 2pm–5pm1 flights—
- 5pm–8pm305 flights79.9%
- 8pm–5am1 flights—
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 89.1% of the time, against 79.9% for the evening window. That is 9 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 305 flights scheduled in it.
Across the year
United on IAD to FLL through the year
July is the worst month at 64.0% on time, 26 points below September, the best at 90.0%. 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. March was the busiest month here, with 84 flights.
Across the week, Wednesday is the strongest day at 91.0% on time and Sunday the weakest at 79.8%, a spread of 11 points.
Arrival by arrival
How late United on IAD to FLL runs when it is late
United on IAD to FLL often beats the schedule: 262 of 693 completed flights, 38%, arrived 15 minutes or more early. The 114 late arrivals split 46 under half an hour, 24 between 30 and 60 minutes, and 44 an hour or more.
- 15+ min early262 flights37.8%
- Within 15 min317 flights45.7%
- 15–29 min late46 flights6.6%
- 30–59 min late24 flights3.5%
- 1–2 hours late21 flights3.0%
- 2+ hours late23 flights3.3%
Scale runs 0% to 100%.
Share of 693 completed flights by arrival against schedule.
27 of 98 late departures made up the time and arrived on time, 28% of them. In the other direction, 43 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at FLL.
The worst days
Worst days for United on IAD to FLL
The latest arrival of the period was on 21 July 2026, 9 hours 4 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The five worst days are spread across July, November, January and August, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 21 July 2026 | 9 hours 4 minutes | Late-arriving aircraft |
| 9 November 2025 | 4 hours 39 minutes | National Airspace System |
| 26 January 2026 | 4 hours 7 minutes | Extreme weather |
| 7 August 2026 | 3 hours 56 minutes | Carrier |
| 10 August 2026 | 3 hours 49 minutes | Late-arriving aircraft |
Delay causes
Why United runs late on this route
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 8,088 reported delay minutes.
- 39%National Airspace System
- 35%Late-arriving aircraft
- 22%Carrier
- 4%Extreme weather
35% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 8,088 reported delay minutes here, that single category outweighs weather by 9 to one. The split is drawn from 8,088 reported delay minutes.
39% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 3,165 minutes out of 8,088, against a national NAS share of 21%.
Cancellations are rare at 0.57%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
6.3% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
The 901 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg runs 85.9% on time across 700 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 699 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking United on IAD to FLL
Put together: treat all of this as provisional. 699 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 83.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 693 completed flights over 12 months sit behind that.
Related
Where to go next
- IAD to FLL, every carrier
- United on FLL to IAD, the return leg
- Frontier Airlines on IAD to FLL47.5%
- United Airlines network-wide record
- Washington Dulles International (IAD) delay statistics
- Fort Lauderdale-Hollywood International (FLL) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.