Carrier route record
UAGRR→DEN
United Airlines · Grand Rapids to Denver
- Flights
- 727
- Period
- September 2025 to August 2026
- Share of route
- 59%
- Carriers
- 4
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on GRR to DEN lands a B+, level with the national rate of 77.3%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 727 flights, with a median arrival 5 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate United on GRR to DEN from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.6%
Arrivals under 15 minutes late, of 718 completed flights
Avg delay
81 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.89%
Whole route
76.1%
Every carrier on GRR to DEN, 1,234 flights
These figures cover 727 flights between September 2025 and August 2026. The median arrival is 5 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 GRR to DEN
United flew 727 of the 1,234 flights on GRR to DEN, most of the route. Its 77.6% on time is 2 points better than the route as a whole, which runs 76.1%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from SkyWest at 100.0% to Southwest at 72.5%. Three 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 |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| United Airlines (this page) | 727 | 77.6% | 81 min | 0.55% | B+ |
| Frontier Airlinesthin sample | 147 | 77.2% | 107 min | 0.00% | B+ |
| Southwest Airlinesthin sample | 359 | 72.5% | 56 min | 0.28% | C+ |
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 727 flights.
- 5am–8am—
- 8am–11am365 flights81.2%
- 11am–2pm—
- 2pm–5pm362 flights73.9%
- 5pm–8pm—
- 8pm–5am—
Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 81.2% on time for the 8am–11am window against 73.9% for 2pm–5pm. Worth taking if the schedule allows, not worth an extra connection. The 8am–11am window is the busiest, with 365 flights scheduled in it.
Across the year
United on GRR to DEN through the year
January is the weak month at 45.9% on time, against 95.2% in October. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. January was the busiest month here, with 62 flights.
Across the week, Tuesday is the strongest day at 83.5% on time and Sunday the weakest at 74.0%, a spread of 10 points.
Arrival by arrival
How late United on GRR to DEN runs when it is late
The 161 late arrivals split 60 under half an hour, 54 between 30 and 60 minutes, and 47 an hour or more.
- 15+ min early162 flights22.6%
- Within 15 min395 flights55.0%
- 15–29 min late60 flights8.4%
- 30–59 min late54 flights7.5%
- 1–2 hours late26 flights3.6%
- 2+ hours late21 flights2.9%
Scale runs 0% to 100%.
Share of 718 completed flights by arrival against schedule.
32 of 146 late departures made up the time and arrived on time, 22% of them. In the other direction, 47 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 DEN.
The worst days
Worst days for United on GRR to DEN
The latest arrival of the period was on 7 June 2026, 22 hours 21 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 7 June 2026 | 22 hours 21 minutes | Carrier |
| 15 January 2026 | 11 hours 31 minutes | Late-arriving aircraft |
| 3 July 2026 | 11 hours 8 minutes | Carrier |
| 31 May 2026 | 7 hours | Carrier |
| 2 October 2025 | 6 hours 57 minutes | Late-arriving aircraft |
Delay causes
Why United runs late on this route
Carrier accounts for 46% of the 13,000 delay minutes carriers reported here, and the remaining four split what is left.
- 46%Carrier
- 26%National Airspace System
- 25%Late-arriving aircraft
- 3%Extreme weather
The largest share of delay minutes, 46%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 5,997 of the 13,000 delay minutes reported here. The split is drawn from 12,960 reported delay minutes.
Cancellations are rare at 0.55%, 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
6.5% 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 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.
The return leg runs 78.3% on time across 727 flights, within half a point 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. 727 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 GRR to DEN
Put together: treat all of this as provisional. 727 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 77.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 718 completed flights over 12 months sit behind that.
Related
Where to go next
- GRR to DEN, every carrier
- United on DEN to GRR, the return leg
- Frontier Airlines on GRR to DEN77.2%
- Southwest Airlines on GRR to DEN72.5%
- United Airlines network-wide record
- Denver International (DEN) delay statistics
- Worst months to fly in the US, ranked by the data
- How to read this site: grades, sample sizes, and honest caveats
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.