Route reliability record
DEN→GRR
Denver to Grand Rapids
- Flights
- 1,239
- Period
- July 2025 to June 2026
- Distance
- 1,015 mi
- Carriers
- 4
This route sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 1,239 DEN to GRR flights, with a median arrival 2 minutes early.
Best time to fly DEN to GRR: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 87.0% of the time and Tuesday flights 79.4%, against 75.3% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
75.3%
Arrivals under 15 minutes late, of 1,233 completed flights
Avg delay
52 min
Across delayed arrivals only, not all flights
Cancelled
0.24%
National rate is 1.81%
Best carrier
United
76.7% on time across 728 flights
These figures cover 1,239 flights between July 2025 and June 2026. The median arrival is 2 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.
Carrier by carrier
Which airline is most reliable on DEN to GRR
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+ |
| Frontier Airlinesthin sample | 147 | 87.1% | 74 min | 0.00% | A+ |
| United Airlines | 728 | 76.7% | 54 min | 0.27% | B+ |
| Southwest Airlinesthin sample | 363 | 67.6% | 45 min | 0.28% | C+ |
Flight by flight
Flights on DEN to GRR
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 25 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am401 flights87.0%
- 11am–2pm134 flights70.1%
- 2pm–5pm216 flights87.0%
- 5pm–8pm482 flights61.8%
- 8pm–5am6 flights—
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 61.8% on time, against 87.0% for the 8am–11am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5pm–8pm window is the busiest, with 482 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 22 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
December is the weak month at 63.7% on time, against 85.3% in April. 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. July was the busiest month here, with 122 flights.
Across the week, Tuesday is the strongest day at 79.4% on time and Sunday the weakest at 70.4%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 50% of the 16,000 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.
- 50%Late-arriving aircraft
- 28%Carrier
- 20%National Airspace System
- 2%Extreme weather
50% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 16,000 reported delay minutes here, that single category outweighs weather by 28 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 15,839 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 87.0% on time here.
Cancellations are rare at 0.24%, below the national 1.81% 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 actually costs
6.8% 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 roughly 50 minutes, 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. 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 return leg is a different operation and performs like one: it runs 78.4% on time across 1,238 flights, 3 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 3 points of difference.
The sample behind these figures is 1,239 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in GRR after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. April runs 85.3% on time and December 63.7%, a swing of 22 points. If the dates move at all, move them out of December before you think about anything else. 1,233 completed flights over 12 months sit behind that.
Common questions
DEN to GRR questions
How often is DEN to GRR delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 24.7% of the 1,239 flights in this analysis, against 22.4% nationally. Delayed flights are late by roughly 50 minutes on average.
How reliable is DEN to GRR compared with the rest of the country?
75.3% of flights arrive on time here against a national 77.6%, a difference of 2 points against it. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on DEN to GRR?
The 8am–11am departure window is the strongest at 87.0% on time. The 5pm–8pm window is the weakest at 61.8%, 25 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are December delays on DEN to GRR?
December is the weakest month at 63.7% on time, compared with 85.3% in April. Across the year that is 22 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- GRR to DEN — the return legseparate record
- Denver International (DEN) delay statistics
- Frontier Airlines on DEN to GRR87.1%
- United Airlines on DEN to GRR76.7%
- Southwest Airlines on DEN to GRR67.6%
- DEN to PHX, a related route75.7%
- ORD to GRR, a related route70.0%
- DEN to SLC, a related route77.5%
- SkyWest Airlines on-time record100.0%
- Frontier Airlines on-time record87.1%
- United Airlines on-time record76.7%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. DEN to GRR and GRR to DEN are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.