Route reliability record
GUC→DEN
Gunnison to Denver
- Flights
- 995
- Period
- July 2025 to June 2026
- Distance
- 152 mi
- Carriers
- 1
This route lands a B+, 3 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 995 GUC to DEN flights, with a median arrival 11 minutes early.
Best time to fly GUC to DEN: a 11am–2pm departure, ideally on a Sunday. Flights in that window arrived on time 87.7% of the time and Sunday flights 84.8%, against 80.6% 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
80.6%
Arrivals under 15 minutes late, of 983 completed flights
Avg delay
85 min
Across delayed arrivals only, not all flights
Cancelled
0.90%
National rate is 1.81%
Best carrier
SkyWest
80.6% on time across 995 flights
These figures cover 995 flights between July 2025 and June 2026. Beyond the headline rate, 9.6% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on GUC to DEN
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 Airlines | 995 | 80.6% | 85 min | 0.90% | B+ |
Flight by flight
Flights on GUC to DEN
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.
Best ways to make this trip
The most reliable ways to fly Gunnison to Denver
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 3 of the top 4 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. MTJ → DENMontrose to Denver | Southwest Airlines | 80.5% | 80.7% | 0.24% | 8am–11am, Thu | — |
| 2. GUC → DENGunnison to Denver | SkyWest Airlines | 79.9% | 80.6% | 0.90% | 11am–2pm, Sun | OO 5602 07:00 |
| 3. MTJ → DENMontrose to Denver | United Airlines | 78.0% | 78.5% | 0.68% | 5am–8am, Wed | — |
| 4. ASE → DENAspen to Denver | SkyWest Airlines | 71.3% | 75.2% | 5.15% | 5am–8am, Wed | OO 5766 07:00 |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 21 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–8am365 flights83.9%
- 8am–11am—
- 11am–2pm364 flights87.7%
- 2pm–5pm266 flights66.3%
- 5pm–8pm—
- 8pm–5am—
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 87.7% on time, ahead of 2pm–5pm at 66.3%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 5am–8am window is the busiest, with 365 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 39 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.
July is the worst month at 56.5% on time, 39 points below April, the best at 95.4%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. January was the busiest month here, with 93 flights.
Across the week, Sunday is the strongest day at 84.8% on time and Saturday the weakest at 74.1%. 11 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
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 16,000 reported delay minutes.
- 42%Carrier
- 24%National Airspace System
- 22%Late-arriving aircraft
- 12%Extreme weather
- 0%Security
Extreme weather accounts for 12% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 1.9 times the usual weather exposure. The split is drawn from 16,276 reported delay minutes.
The largest share of delay minutes, 42%, 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 6,813 of the 16,000 delay minutes reported here.
Cancellations sit at 0.90% against a national 1.81%, which is ordinary. Diversions add another 0.30%.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.6% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
At 152 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 11am–2pm window matters as much as it does.
The return leg runs 81.3% on time across 995 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. 995 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.
Work out the risk of missing a connection in DEN after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 995 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 80.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 983 completed flights over 12 months sit behind that.
Common questions
GUC to DEN questions
How often is GUC to DEN delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 19.4% of the 995 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is GUC to DEN compared with the rest of the country?
80.6% of flights arrive on time here against a national 77.6%, a difference of 3 points in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on GUC to DEN?
The 11am–2pm departure window is the strongest at 87.7% on time. The 2pm–5pm window is the weakest at 66.3%, 21 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 July delays on GUC to DEN?
July is the weakest month at 56.5% on time, compared with 95.4% in April. Across the year that is 39 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
- DEN to GUC — the return legseparate record
- Denver International (DEN) delay statistics
- PHX to DEN, a related route77.2%
- SLC to DEN, a related route77.8%
- LAX to DEN, a related route81.7%
- SkyWest Airlines on-time record80.6%
- How often a connection fails at the major US hubs
- The best time of day to fly, according to 7.04 million flight records
Direction matters. GUC to DEN and DEN to GUC 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.