Flight number record
UA 2637
United Airlines · Denver to Grand Rapids
- Route
- DEN → GRR
- Departs
- 09:50
- Flights
- 278
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 2637, check with United Airlines.
UA 2637 earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 11 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 40 minutes. That rests on 278 flights, with a median arrival 7 minutes early.
Set against the rest of the country, UA 2637's record is 11 points better than the US average of 77.6%. That gap is worth roughly 105 fewer late arrivals for every thousand flights.
Key figures
On time
88.1%
Arrivals under 15 minutes late, of 278 completed flights
Avg delay
39 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.81%
1 hour+ late
2.5%
National rate is 8.1%
These figures cover 278 flights between July 2025 and June 2026. The median arrival is 7 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 2637 flies
UA 2637 flies DEN to GRR without a single fixed slot. Its most common scheduled departure was 09:50, used on 77 of 278 flights, with 09:58 (41 flights) and 10:06 (37 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 09:5077 flights27.7%
- Departs 09:5841 flights14.7%
- Departs 10:0637 flights13.3%
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 09:50 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and UA 2637 runs 4 points better at 88.1%. 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 2637 next to DEN to GRR
Every carrier on DEN to GRR combined arrived on time 75.3% of the time across 1,239 flights, so UA 2637 is 13 points ahead of it. United flew 728 flights on the same city pair under all its flight numbers, including this one, and those ran 76.7% on time. Across its whole network United Airlines managed 79.0%, which this flight beats by 9 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 2637thin sample | 278 | 88.1% | 39 min | 0.00% | A+ |
| All United Airlines on DEN–GRR | 728 | 76.7% | 54 min | 0.27% | B+ |
| All carriers on DEN–GRR | 1,239 | 75.3% | 52 min | 0.24% | B+ |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 2637 quarter by quarter
Quarter by quarter UA 2637 held fairly steady: 88.0% in Oct–Dec 2025, 88.8% in Jan–Mar 2026 and 86.8% in Apr–Jun 2026. A spread of 2 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 20256 flights—
- Oct–Dec 202592 flights88.0%
- Jan–Mar 202689 flights88.8%
- Apr–Jun 202691 flights86.8%
Scale runs 80% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, UA 2637 did best on Thursday at 95.0% on time and worst on Sunday at 80.0%. Each day rests on about 40 flights, so a gap of 15 points is worth noticing but could still narrow in another year.
Delay causes
Why UA 2637 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 1,278 reported delay minutes.
- 36%Carrier
- 34%Late-arriving aircraft
- 30%National Airspace System
The largest share of delay minutes, 36%, 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 457 of the 1,278 delay minutes reported here. The split is drawn from 1,278 delay minutes reported on UA 2637.
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
Badly late arrivals are rare here: only 2.5% land an hour or more behind schedule, against 8.1% 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 1,015 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 two other city pairs in the data, including EGE to DEN (68) and DEN to PHL (18), but none flew often enough under UA 2637 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DEN to GRR only.
One caution: this is a thin sample. 278 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 2637
For a booking, UA 2637 has one of the better records a US domestic flight can show: 88.1% on time and 0.00% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- DEN to GRR, every carrier and departure
- GRR to DEN, the return direction
- 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
- 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.