Carrier route record
WNGEG→PHX
Southwest Airlines · Spokane to Phoenix
- Flights
- 618
- Period
- September 2025 to August 2026
- Share of route
- 49%
- Carriers
- 4
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on GEG to PHX earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 50 minutes. That rests on 618 flights, with a median arrival 6 minutes early.
Set against the rest of the country, Southwest's GEG to PHX record is 8 points better than the US average of 77.3%. That gap is worth roughly 75 fewer late arrivals for every thousand flights.
Key figures
On time
84.8%
Arrivals under 15 minutes late, of 612 completed flights
Avg delay
49 min
Across delayed arrivals only, not all flights
Cancelled
0.49%
National rate is 1.89%
Whole route
83.3%
Every carrier on GEG to PHX, 1,264 flights
These figures cover 618 flights between September 2025 and August 2026. The median arrival is 6 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.
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Carrier by carrier
Southwest against every carrier on GEG to PHX
Southwest flew 618 of the 1,264 flights on GEG to PHX, about 49% of it. Its 84.8% on time is 2 points better than the route as a whole, which runs 83.3%. Ranked by on-time rate it is first of four carriers on the route, where the range runs from Southwest at 84.8% 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) | 618 | 84.8% | 49 min | 0.49% | B+ |
| American Airlines | 591 | 83.5% | 121 min | 0.34% | B+ |
| Envoy Airthin sample | 10 | 70.0% | 38 min | 0.00% | C+ |
| Frontier Airlinesthin sample | 45 | 63.6% | 64 min | 2.22% | D |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 29 points, against half a point between the best and worst carrier.
- 5am–8am271 flights94.8%
- 8am–11am61 flights93.3%
- 11am–2pm66 flights83.3%
- 2pm–5pm150 flights72.7%
- 5pm–8pm70 flights66.2%
- 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 94.8% of the time, against 66.2% for the evening window. That is 29 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 271 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 September, the best at 94.7%. 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 92.1% on time and Tuesday the weakest at 73.7%, a spread of 18 points.
Arrival by arrival
How late Southwest on GEG to PHX runs when it is late
The 93 late arrivals split 36 under half an hour, 34 between 30 and 60 minutes, and 23 an hour or more.
- 15+ min early142 flights23.2%
- Within 15 min377 flights61.6%
- 15–29 min late36 flights5.9%
- 30–59 min late34 flights5.6%
- 1–2 hours late18 flights2.9%
- 2+ hours late5 flights0.8%
Scale runs 0% to 100%.
Share of 612 completed flights by arrival against schedule.
A late pushback is often recovered here: of 122 departures that left 15 minutes late or more, 38 still arrived on time. Only 9 left on time and still arrived late.
The worst days
Worst days for Southwest on GEG to PHX
The latest arrival of the period was on 26 December 2025, 3 hours 28 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On three of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 26 December 2025 | 3 hours 28 minutes | Late-arriving aircraft |
| 16 August 2026 | 3 hours 14 minutes | Carrier |
| 28 December 2025 | 2 hours 17 minutes | Carrier |
| 2 July 2026 | 2 hours 16 minutes | Late-arriving aircraft |
| 13 October 2025 | 2 hours 13 minutes | Carrier |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 54% of the 4,552 delay minutes carriers reported here, and the remaining four split what is left.
- 54%Late-arriving aircraft
- 30%Carrier
- 16%National Airspace System
- 0%Extreme weather
54% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 4,552 reported delay minutes here, that single category outweighs weather by 54 to one. The split is drawn from 4,552 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 94.8% on time here.
Cancellations are rare at 0.49%, below the national 1.89% 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 3.8% land an hour or more behind schedule, against 8.3% 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.
The return leg is a different operation and performs like one: it runs 73.9% on time across 618 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. 618 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. 618 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 84.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 612 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 PHX83.5%
- 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 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.