Flight number record
UA 1424
United Airlines · Denver to Seattle
- Route
- DEN → SEA
- Departs
- 11:50
- Flights
- 268
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 1424, check with United Airlines.
UA 1424 earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 268 flights, with a median arrival 6 minutes early.
Set against the rest of the country, UA 1424's record is 8 points better than the US average of 77.3%. That gap is worth roughly 84 fewer late arrivals for every thousand flights.
Key figures
On time
85.7%
Arrivals under 15 minutes late, of 266 completed flights
Avg delay
68 min
Across delayed arrivals only, not all flights
Cancelled
0.75%
National rate is 1.89%
1 hour+ late
4.5%
National rate is 8.3%
These figures cover 268 flights between September 2025 and August 2026. The median arrival is 6 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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Schedule
When UA 1424 flies
UA 1424 flies DEN to SEA without a single fixed slot. Its most common scheduled departure was 11:50, used on 88 of 268 flights, with 11:15 (53 flights) and 11:42 (40 flights) next.
- Departs 11:5088 flights32.8%
- Departs 11:1553 flights19.8%
- Departs 11:4240 flights14.9%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 11:50 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and UA 1424 runs 7 points better at 85.7%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
UA 1424 next to DEN to SEA
Every carrier on DEN to SEA combined arrived on time 74.5% of the time across 6,328 flights, so UA 1424 is 11 points ahead of it. United flew 1,908 flights on the same city pair under all its flight numbers, including this one, and those ran 80.9% on time. Across its whole network United Airlines managed 78.8%, which this flight beats by 7 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1424thin sample | 268 | 85.7% | 68 min | 0.75% | A+ |
| All United Airlines on DEN–SEA | 1,908 | 80.9% | 57 min | 0.47% | B+ |
| All carriers on DEN–SEA | 6,328 | 74.5% | 58 min | 0.60% | C+ |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | B |
Across the year
UA 1424 quarter by quarter
Quarter by quarter UA 1424 held fairly steady: 89.2% in Oct–Dec 2025, 81.2% in Jan–Mar 2026, 86.8% in Apr–Jun 2026 and 85.4% in Jul–Sep 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Oct–Dec 202567 flights89.2%
- Jan–Mar 202669 flights81.2%
- Apr–Jun 202691 flights86.8%
- Jul–Sep 202641 flights85.4%
Scale runs 75% to 95%.
By weekday, UA 1424 did best on Tuesday at 92.1% on time and worst on Wednesday at 76.3%. Each day rests on about 38 flights, so a gap of 16 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 1424 runs when it is late
UA 1424 often beats the schedule: 71 of 266 completed flights, 27%, arrived 15 minutes or more early. The 38 late arrivals split 9 under half an hour, 17 between 30 and 60 minutes, and 12 an hour or more.
- 15+ min early71 flights26.7%
- Within 15 min157 flights59.0%
- 15–29 min late9 flights3.4%
- 30–59 min late17 flights6.4%
- 1–2 hours late6 flights2.3%
- 2+ hours late6 flights2.3%
Scale runs 0% to 100%.
Share of 266 completed flights by arrival against schedule.
11 of 37 late departures made up the time and arrived on time, 30% of them. 12 flights left on time and still arrived late.
The worst days
Worst days for UA 1424
The latest arrival of the period was on 13 March 2026, 4 hours 59 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. The five worst days are spread across March, January and December, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 March 2026 | 4 hours 59 minutes | National Airspace System |
| 31 January 2026 | 3 hours 42 minutes | Carrier |
| 24 December 2025 | 3 hours 26 minutes | Late-arriving aircraft |
| 19 December 2025 | 2 hours 57 minutes | Carrier |
| 15 March 2026 | 2 hours 34 minutes | Late-arriving aircraft |
Delay causes
Why UA 1424 runs late
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 2,580 reported delay minutes.
- 37%Late-arriving aircraft
- 36%National Airspace System
- 27%Carrier
37% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 2,580 reported delay minutes here, that single category outweighs weather by 37 to one. The split is drawn from 2,580 delay minutes reported on UA 1424.
Cancellations are rare at 0.75%, 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 routes
What a delay on this flight costs
Badly late arrivals are rare here: only 4.5% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 1,024 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 same number turns up on six other city pairs in the data, including SEA to SFO (73), FLL to DEN (55) and OKC to DEN (46), but none flew often enough under UA 1424 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DEN to SEA only.
One caution: this is a thin sample. 268 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 UA 1424
For a booking, UA 1424 has one of the better records a US domestic flight can show: 85.7% on time and 0.75% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- DEN to SEA, every carrier and departure
- SEA to DEN, the return direction
- Delta Air Lines 1731 on the same route89.4%
- United Airlines 2271 on the same route91.9%
- Alaska Airlines 643 on the same route89.5%
- United Airlines 2013 on the same route77.9%
- Denver International (DEN) delay statistics
- Seattle-Tacoma International (SEA) delay statistics
- United Airlines on-time record
- Every United Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means United Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
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.