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DelayAtlas

Carrier route record

DLSLCPHX

Delta Air Lines · Salt Lake City to Phoenix

Flights
1,708
Period
July 2025 to June 2026
Share of route
30%
Carriers
6
A+GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.

Delta on SLC to PHX earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 10 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 1,708 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 1,159 at 86.5% on time.

Set against the rest of the country, Delta's SLC to PHX record is 10 points better than the US average of 77.6%. That gap is worth roughly 103 fewer late arrivals for every thousand flights.

Key figures

On time

87.9%

Arrivals under 15 minutes late, of 1,697 completed flights

Avg delay

56 min

Across delayed arrivals only, not all flights

Cancelled

0.53%

National rate is 1.81%

Whole route

83.9%

Every carrier on SLC to PHX, 5,759 flights

These figures cover 1,708 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

Delta against every carrier on SLC to PHX

Delta flew 1,708 of the 5,759 flights on SLC to PHX, about 30% of it. Its 87.9% on time is 4 points better than the route as a whole, which runs 83.9%. Ranked by on-time rate it is first 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. SkyWest Airlines arrives on time 86.5% 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.

On-time performance by carrier on SLC to PHX
AirlineFlightsOn timeAvg delayCancelledGrade
Delta Air Lines (this page)1,70887.9%56 min0.53%A+
SkyWest Airlines1,15986.5%111 min0.26%A+
American Airlinesthin sample26684.5%108 min0.38%B+
Envoy Airthin sample8981.6%45 min1.12%B
Frontier Airlines67781.5%89 min1.48%B
Southwest Airlines1,86079.6%55 min0.43%B+

SkyWest leads Southwest by 7 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Flight by flight

Delta flight numbers on SLC to PHX

Departure window

When Delta runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 13 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am115 flights97.3%
  • 8am–11am248 flights93.9%
  • 11am–2pm365 flights85.4%
  • 2pm–5pm365 flights84.1%
  • 5pm–8pm251 flights89.2%
  • 8pm–5am364 flights86.2%

Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 97.3% of the time, against 84.1% for the afternoon window. That is 13 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 365 flights scheduled in it.

Across the year

Delta on SLC to PHX through the year

On-time rate by calendar month89J85F88M90A96M91J86J88A94S82O84N82D
Darker means more delays. Figures are on-time percentages.May best, October worst

May is the best month on the calendar at 95.9% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. December was the busiest month here, with 150 flights.

Across the week, Tuesday is the strongest day at 91.5% on time and Sunday the weakest at 84.0%. 8 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week86.5Mon91.5Tue88.4Wed87.9Thu90.4Fri86.2Sat84.0Sun
Monday: 86.5 percent on time. Tuesday: 91.5 percent on time. Wednesday: 88.4 percent on time. Thursday: 87.9 percent on time. Friday: 90.4 percent on time. Saturday: 86.2 percent on time. Sunday: 84.0 percent on time

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Carrier accounts for 56% 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.

  • Carrier
    56%
  • Late-arriving aircraft
    22%
  • National Airspace System
    21%
  • Extreme weather
    1%

The largest share of delay minutes, 56%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 6,464 of the 11,000 delay minutes reported here. The split is drawn from 11,494 reported delay minutes.

Cancellations are rare at 0.53%, 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 3.7% 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 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 90.4% on time across 1,708 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 1,708 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.

What to do with this

Booking Delta on SLC to PHX

Put together: the calendar is the biggest lever here, not the carrier or the hour. May runs 95.9% on time and October 81.6%, a swing of 14 points. If the dates move at all, move them out of October before you think about anything else. 1,697 completed flights over 12 months sit behind that.

Related

Where to go next

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.