Carrier route record
F9SLC→PHX
Frontier Airlines · Salt Lake City to Phoenix
- Flights
- 677
- Period
- July 2025 to June 2026
- Share of route
- 12%
- Carriers
- 6
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on SLC to PHX lands a B, 4 points better than the national rate of 77.6%. Roughly 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 677 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 1,708 at 87.9% on time.
Delta Air Lines is the most reliable of the three carriers covered here at 87.9% on time across 1,708 flights.
Key figures
On time
81.5%
Arrivals under 15 minutes late, of 665 completed flights
Avg delay
89 min
Across delayed arrivals only, not all flights
Cancelled
1.48%
National rate is 1.81%
Whole route
83.9%
Every carrier on SLC to PHX, 5,759 flights
These figures cover 677 flights between July 2025 and June 2026. The median arrival is 14 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
Frontier against every carrier on SLC to PHX
Frontier flew 677 of the 5,759 flights on SLC to PHX, about 12% of it. Its 81.5% on time is 2 points worse than the route as a whole, which runs 83.9%. Ranked by on-time rate it is number five of six carriers on the route, where the range runs from Delta at 87.9% to Southwest at 79.6%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 87.9% of the time; Southwest Airlines manages 79.6%. Sample sizes sit next to every figure, because a two-point gap across 1,860 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 1,708 | 87.9% | 56 min | 0.53% | A+ |
| SkyWest Airlines | 1,159 | 86.5% | 111 min | 0.26% | A+ |
| American Airlinesthin sample | 266 | 84.5% | 108 min | 0.38% | B+ |
| Envoy Airthin sample | 89 | 81.6% | 45 min | 1.12% | B |
| Frontier Airlines (this page) | 677 | 81.5% | 89 min | 1.48% | B |
| Southwest Airlines | 1,860 | 79.6% | 55 min | 0.43% | B+ |
Delta leads Southwest by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Departure window
When Frontier runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 16 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am68 flights89.6%
- 11am–2pm216 flights90.2%
- 2pm–5pm142 flights75.7%
- 5pm–8pm66 flights76.9%
- 8pm–5am185 flights74.3%
Scale runs 65% 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 90.2% on time, ahead of 8pm–5am at 74.3%. 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 11am–2pm window is the busiest, with 216 flights scheduled in it.
Across the year
Frontier on SLC to PHX through the year
Delays peak in November, when the on-time rate falls to 62.0%. March is the strongest month at 93.2%. Moving a flexible trip across that boundary buys 31 points. March was the busiest month here, with 73 flights.
Across the week, Tuesday is the strongest day at 94.4% on time and Sunday the weakest at 77.5%. 17 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Frontier runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 78% of the 11,000 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.
- 78%Late-arriving aircraft
- 14%National Airspace System
- 9%Carrier
78% 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 11,000 reported delay minutes here, that single category outweighs weather by 78 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 10,976 reported delay minutes.
Cancellations sit at 1.48% against a national 1.81%, which is ordinary. Diversions add another 0.30%.
Connections and stage length
What a delay here costs
7.8% 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 an hour and a half, which a normal layover absorbs.
The 507 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 runs 83.6% on time across 677 flights, within 2 points 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. 677 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 Frontier on SLC to PHX
Put together: treat all of this as provisional. 677 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 81.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 665 completed flights over 12 months sit behind that.
Related
Where to go next
- SLC to PHX, every carrier
- Frontier on PHX to SLC, the return leg
- Delta Air Lines on SLC to PHX87.9%
- SkyWest Airlines on SLC to PHX86.5%
- American Airlines on SLC to PHX84.5%
- Southwest Airlines on SLC to PHX79.6%
- Frontier Airlines network-wide record
- Salt Lake City International (SLC) delay statistics
- 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.