Carrier route record
WNDEN→GEG
Southwest Airlines · Denver to Spokane
- Flights
- 857
- Period
- July 2025 to June 2026
- Share of route
- 42%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on DEN to GEG sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 8 points worse than the national rate of 77.6%. The late ones land roughly 50 minutes behind schedule. That rests on 857 flights, with a median arrival 3 minutes late.
The national on-time rate over the same period is 77.6%, so Southwest on DEN to GEG runs 8 points behind the country as a whole. Across a thousand flights that is about 75 extra late arrivals.
Key figures
On time
70.1%
Arrivals under 15 minutes late, of 853 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.35%
National rate is 1.81%
Whole route
75.2%
Every carrier on DEN to GEG, 2,062 flights
These figures cover 857 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.
Carrier by carrier
Southwest against every carrier on DEN to GEG
Southwest flew 857 of the 2,062 flights on DEN to GEG, about 42% of it. Its 70.1% on time is 5 points worse than the route as a whole, which runs 75.2%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from SkyWest at 90.3% to Southwest at 70.1%. Two 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 | 250 | 90.3% | 47 min | 0.80% | A+ |
| Frontier Airlinesthin sample | 122 | 86.1% | 34 min | 0.00% | A+ |
| United Airlines | 833 | 74.3% | 53 min | 0.24% | C+ |
| Southwest Airlines (this page) | 857 | 70.1% | 48 min | 0.35% | C+ |
Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 34 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–8am31 flights87.1%
- 8am–11am330 flights86.6%
- 11am–2pm19 flights—
- 2pm–5pm115 flights68.4%
- 5pm–8pm23 flights—
- 8pm–5am339 flights52.8%
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 52.8% on time, against 87.1% for the 5am–8am 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 8pm–5am window is the busiest, with 339 flights scheduled in it.
Across the year
Southwest on DEN to GEG through the year
Delays peak in March, when the on-time rate falls to 55.7%. January is the strongest month at 83.9%. Moving a flexible trip across that boundary buys 28 points. July was the busiest month here, with 93 flights.
Across the week, Tuesday is the strongest day at 74.6% on time and Friday the weakest at 63.9%. 11 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Southwest runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 57% of the 12,000 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.
- 57%Late-arriving aircraft
- 31%Carrier
- 10%National Airspace System
- 2%Extreme weather
57% 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 12,000 reported delay minutes here, that single category outweighs weather by 38 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 12,300 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 87.1% on time here.
Cancellations are rare at 0.35%, 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 costs
7.3% 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 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 82.4% on time across 858 flights, 12 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 12 points of difference.
One caution: this is a thin sample. 857 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 Southwest on DEN to GEG
Put together: treat all of this as provisional. 857 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 70.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 853 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to GEG, every carrier
- Southwest on GEG to DEN, the return leg
- SkyWest Airlines on DEN to GEG90.3%
- Frontier Airlines on DEN to GEG86.1%
- United Airlines on DEN to GEG74.3%
- Southwest Airlines network-wide record
- Denver International (DEN) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.