Carrier route record
WNGEG→PHX
Southwest Airlines · Spokane to Phoenix
- Flights
- 603
- Period
- July 2025 to June 2026
- Share of route
- 49%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on GEG to PHX earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 45 minutes. That rests on 603 flights, with a median arrival 7 minutes early.
Set against the rest of the country, Southwest's GEG to PHX record is 9 points better than the US average of 77.6%. That gap is worth roughly 90 fewer late arrivals for every thousand flights.
Key figures
On time
86.6%
Arrivals under 15 minutes late, of 598 completed flights
Avg delay
47 min
Across delayed arrivals only, not all flights
Cancelled
0.50%
National rate is 1.81%
Whole route
84.1%
Every carrier on GEG to PHX, 1,235 flights
These figures cover 603 flights between July 2025 and June 2026. The median arrival is 7 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
Southwest against every carrier on GEG to PHX
Southwest flew 603 of the 1,235 flights on GEG to PHX, about 49% of it. Its 86.6% on time is 3 points better than the route as a whole, which runs 84.1%. Ranked by on-time rate it is first of four carriers on the route, where the range runs from Southwest at 86.6% to Frontier at 63.6%. 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 |
|---|---|---|---|---|---|
| Southwest Airlines (this page) | 603 | 86.6% | 47 min | 0.50% | A+ |
| American Airlines | 577 | 83.4% | 110 min | 0.00% | B+ |
| Envoy Airthin sample | 10 | 70.0% | 38 min | 0.00% | C+ |
| Frontier Airlinesthin sample | 45 | 63.6% | 64 min | 2.22% | D |
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 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–8am291 flights95.1%
- 8am–11am57 flights92.9%
- 11am–2pm54 flights85.2%
- 2pm–5pm143 flights74.1%
- 5pm–8pm58 flights70.2%
- 8pm–5am—
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 95.1% of the time, against 70.2% for the evening window. That is 25 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 291 flights scheduled in it.
Across the year
Southwest on GEG to PHX through the year
June is the worst month at 73.6% on time, 21 points below July, the best at 94.9%. 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. March was the busiest month here, with 62 flights.
Across the week, Saturday is the strongest day at 92.2% on time and Tuesday the weakest at 77.9%. 14 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 52% of the 3,721 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.
- 52%Late-arriving aircraft
- 29%Carrier
- 19%National Airspace System
- 0%Extreme weather
52% 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 3,721 reported delay minutes here, that single category outweighs weather by 52 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 3,721 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 95.1% on time here.
Cancellations are rare at 0.50%, 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
Badly late arrivals are rare here: only 3.2% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 1,020 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 75.6% on time across 603 flights, 11 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 11 points of difference.
One caution: this is a thin sample. 603 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 GEG to PHX
Put together: treat all of this as provisional. 603 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 86.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 598 completed flights over 12 months sit behind that.
Related
Where to go next
- GEG to PHX, every carrier
- Southwest on PHX to GEG, the return leg
- American Airlines on GEG to PHX83.4%
- Southwest Airlines network-wide record
- Phoenix Sky Harbor International (PHX) 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.