Flight number record
UA 1727
United Airlines · Buffalo to Denver
- Route
- BUF → DEN
- Departs
- 08:25
- Flights
- 293
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 1727, check with United Airlines.
UA 1727 earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 6 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 293 flights, with a median arrival 3 minutes early.
Set against the rest of the country, UA 1727's record is 6 points better than the US average of 77.6%. That gap is worth roughly 64 fewer late arrivals for every thousand flights.
Key figures
On time
84.0%
Arrivals under 15 minutes late, of 293 completed flights
Avg delay
76 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.81%
1 hour+ late
5.8%
National rate is 8.1%
These figures cover 293 flights between July 2025 and June 2026. The median arrival is 3 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.
Schedule
When UA 1727 flies
UA 1727 flies BUF to DEN without a single fixed slot. Its most common scheduled departure was 08:25, used on 101 of 293 flights, with 09:00 (41 flights) and 08:30 (40 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 08:25101 flights34.5%
- Departs 09:0041 flights14.0%
- Departs 08:3040 flights13.7%
Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 08:25 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and UA 1727 runs level with that at 84.0%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
Against the route
UA 1727 next to BUF to DEN
Every carrier on BUF to DEN combined arrived on time 76.8% of the time across 600 flights, so UA 1727 is 7 points ahead of it. Across its whole network United Airlines managed 79.0%, which this flight beats by 5 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 1727thin sample | 293 | 84.0% | 76 min | 0.00% | B+ |
| All United Airlines on BUF–DENthin sample | 293 | 84.0% | 76 min | 0.00% | B+ |
| All carriers on BUF–DEN | 600 | 76.8% | 59 min | 0.17% | B+ |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 1727 quarter by quarter
UA 1727 did not run the same all year. Its best quarter was Jul–Sep 2025 at 90.2% on time and its weakest Jan–Mar 2026 at 66.7%, a swing of 24 points on roughly 73 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202592 flights90.2%
- Oct–Dec 202562 flights85.5%
- Jan–Mar 202648 flights66.7%
- Apr–Jun 202691 flights85.7%
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, UA 1727 did best on Thursday at 92.9% on time and worst on Tuesday at 73.8%. Each day rests on about 42 flights, so a gap of 19 points is worth noticing but could still narrow in another year.
Delay causes
Why UA 1727 runs late
One category carries most of the weight here. Carrier accounts for 58% of the 3,553 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 58%Carrier
- 25%Late-arriving aircraft
- 15%National Airspace System
- 2%Extreme weather
The largest share of delay minutes, 58%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 2,046 of the 3,553 delay minutes reported here. The split is drawn from 3,553 delay minutes reported on UA 1727.
Cancellations are rare at 0.00%, below the national 1.81% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.
Connections and routes
What a delay on this flight costs
5.8% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says 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 1,359 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The same number turns up on three other city pairs in the data, including JAC to DEN (37), EWR to CLE (19) and IAH to BWI (16), but none flew often enough under UA 1727 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to BUF to DEN only.
One caution: this is a thin sample. 293 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 1727
For a booking, read UA 1727 as 84.0% on time with 0.00% cancelled over 293 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- Denver International (DEN) 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
- Worst months to fly in the US, ranked by the data
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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.