Route reliability record
GEG→DEN
Spokane to Denver
- Flights
- 2,063
- Period
- July 2025 to June 2026
- Distance
- 836 mi
- Carriers
- 4
This route lands a B+, 6 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 2,063 GEG to DEN flights, of which United Airlines flew 833 at 85.4% on time.
Best time to fly GEG to DEN: a 5am–8am departure, ideally on a Sunday. Flights in that window arrived on time 96.7% of the time and Sunday flights 90.2%, against 83.8% for the route overall.
Set against the rest of the country, this route's record is 6 points better than the US average of 77.6%. That gap is worth roughly 62 fewer late arrivals for every thousand flights.
Key figures
On time
83.8%
Arrivals under 15 minutes late, of 2,047 completed flights
Avg delay
68 min
Across delayed arrivals only, not all flights
Cancelled
0.24%
National rate is 1.81%
Best carrier
United
85.4% on time across 833 flights
These figures cover 2,063 flights between July 2025 and June 2026. The median arrival is 8 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 GEG to DEN
The two carriers here are closely matched: 3 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlinesthin sample | 250 | 86.7% | 105 min | 0.80% | A+ |
| United Airlines | 833 | 85.4% | 83 min | 0.36% | A+ |
| Southwest Airlines | 858 | 82.4% | 54 min | 0.00% | B+ |
| Frontier Airlinesthin sample | 122 | 77.7% | 36 min | 0.00% | B+ |
No carrier stands out. United tops the table at 85.4%, 3 points clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
Flights on GEG 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 Spokane to Denver
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. GEG → DENSpokane to Denver | United Airlines | 85.1% | 85.4% | 0.36% | 5am–8am, Sat | UA 1255 13:37 |
| 2. GEG → DENSpokane to Denver | Southwest Airlines | 82.4% | 82.4% | 0.00% | 5am–8am, Sun | — |
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 26 points, against 3 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am723 flights96.7%
- 8am–11am83 flights90.4%
- 11am–2pm666 flights78.5%
- 2pm–5pm526 flights73.5%
- 5pm–8pm63 flights70.5%
- 8pm–5am2 flights—
Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 96.7% of the time, against 70.5% for the evening window. That is 26 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 723 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 20 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 72.2% on time, 20 points below November, the best at 91.9%. 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. July was the busiest month here, with 198 flights.
Across the week, Sunday is the strongest day at 90.2% on time and Thursday the weakest at 79.4%. 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 23,000 reported delay minutes.
- 34%Late-arriving aircraft
- 33%National Airspace System
- 27%Carrier
- 7%Extreme weather
34% 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 23,000 reported delay minutes here, that single category outweighs weather by 5 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 22,518 reported delay minutes.
33% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 7,325 minutes out of 23,000, against a national NAS share of 21%.
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
5.5% 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 836 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 75.2% on time across 2,062 flights, 9 points below 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 9 points of difference.
The sample behind these figures is 2,063 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 DEN 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. November runs 91.9% on time and July 72.2%, a swing of 20 points. If the dates move at all, move them out of July before you think about anything else. 2,047 completed flights over 12 months sit behind that.
Common questions
GEG to DEN questions
How often is GEG to DEN delayed?
About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 16.2% of the 2,063 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on GEG to DEN?
United Airlines leads at 85.4% on time across 833 flights. Southwest Airlines is at the other end on 82.4%, a gap of 3 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on GEG to DEN?
The 5am–8am departure window is the strongest at 96.7% on time. The 5pm–8pm window is the weakest at 70.5%, 26 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 GEG to DEN?
July is the weakest month at 72.2% on time, compared with 91.9% in November. Across the year that is 20 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 GEG — the return legseparate record
- Denver International (DEN) delay statistics
- SkyWest Airlines on GEG to DEN86.7%
- United Airlines on GEG to DEN85.4%
- Southwest Airlines on GEG to DEN82.4%
- Frontier Airlines on GEG to DEN77.7%
- GEG to SEA, a related route85.9%
- PHX to DEN, a related route77.2%
- GEG to SLC, a related route90.6%
- SkyWest Airlines on-time record86.7%
- United Airlines on-time record85.4%
- Southwest Airlines on-time record82.4%
- 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. GEG to DEN and DEN to GEG 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.