Route reliability record
PDX→SLC
Portland to Salt Lake City
- Flights
- 2,383
- Period
- September 2025 to August 2026
- Distance
- 630 mi
- Carriers
- 4
This route 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 12 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 2,383 PDX to SLC flights, of which Delta Air Lines flew 1,696 at 90.8% on time.
Best time to fly PDX to SLC: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 93.1% of the time and Tuesday flights 94.5%, against 89.1% for the route overall.
Set against the rest of the country, this route's record is 12 points better than the US average of 77.3%. That gap is worth roughly 118 fewer late arrivals for every thousand flights.
Key figures
On time
89.1%
Arrivals under 15 minutes late, of 2,355 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
1.09%
National rate is 1.89%
Best carrier
Delta
90.8% on time across 1,696 flights
These figures cover 2,383 flights between September 2025 and August 2026. The median arrival is 10 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
Which airline is most reliable on PDX to SLC
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 90.8% of the time; SkyWest Airlines manages 84.6%. Sample sizes sit next to every figure, because a two-point gap across 614 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Alaska Airlinesthin sample | 47 | 93.6% | 34 min | 0.00% | A+ |
| Delta Air Lines | 1,696 | 90.8% | 61 min | 1.47% | A |
| SkyWest Airlines | 614 | 84.6% | 67 min | 0.16% | B+ |
| Frontier Airlinesthin sample | 26 | 73.1% | 104 min | 0.00% | C+ |
Delta leads SkyWest by 6 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Flights on PDX to SLC
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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Best ways to make this trip
The most reliable ways to fly Portland to Salt Lake City
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. PDX → SLCPortland to Salt Lake City | Delta Air Lines | 89.5% | 90.8% | 1.47% | 5am–8am, Tue | DL 1270 05:45 |
| 2. PDX → SLCPortland to Salt Lake City | SkyWest Airlines | 84.5% | 84.6% | 0.16% | 11am–2pm, Wed | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 2,383 flights.
- 5am–8am539 flights93.1%
- 8am–11am387 flights90.7%
- 11am–2pm463 flights87.1%
- 2pm–5pm195 flights90.2%
- 5pm–8pm799 flights86.4%
- 8pm–5am—
Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 93.1% on time for the 5am–8am window against 86.4% for 5pm–8pm. Worth taking if the schedule allows, not worth an extra connection. The 5pm–8pm window is the busiest, with 799 flights scheduled in it.
Explore
Filter PDX to SLC by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On PDX to SLC, the best departure window is 5am–8am at 93.1% on time and the worst is 5pm–8pm at 86.4%, a real gap of 6.7 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am93.1%
- 8–11am90.7%
- 11am–2pm87.1%
- 2–5pm90.2%
- 5–8pm86.4%
- 8pm–5am—
best all US flightsScale 60% to 100%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
Twelve months, one bar each, drawn from the same 2,383 flights. The strip shows how much of this route's record is set by the calendar rather than by the operation.
August is the worst month at 83.9% on time, 9 points below April, the best at 92.9%. 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. July was the busiest month here, with 240 flights.
Across the week, Tuesday is the strongest day at 94.5% on time and Sunday the weakest at 85.0%, a spread of 10 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 50% of the 16,000 delay minutes carriers reported here, and the remaining four split what is left.
- 50%Late-arriving aircraft
- 36%Carrier
- 10%National Airspace System
- 5%Extreme weather
50% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 16,000 reported delay minutes here, that single category outweighs weather by 11 to one. The split is drawn from 16,384 reported delay minutes.
The largest share of delay minutes, 36%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 5,864 of the 16,000 delay minutes reported here.
Cancellations sit at 1.09% against a national 1.89%, which is ordinary. Diversions add another 0.08%.
Connections and stage length
What a delay here actually 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 630 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 runs 87.9% on time across 2,384 flights, within about a point 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 2,383 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.
Work out the risk of missing a connection in SLC after this flight
What to do with this
Booking this route
Put together: take the 5am–8am departure, avoid August if the dates are flexible, and if two carriers are within a few dollars of each other, Delta is the one with the record behind it. None of that guarantees an on-time arrival; it moves the odds by 7 points, which is the most any booking decision can do. 2,355 completed flights over 12 months sit behind that.
Common questions
PDX to SLC questions
How often is PDX to SLC delayed?
About one flight in nine arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 10.9% of the 2,383 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on PDX to SLC?
Delta Air Lines leads at 90.8% on time across 1,696 flights. SkyWest Airlines is at the other end on 84.6%, a gap of 6 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on PDX to SLC?
The 5am–8am departure window is the strongest at 93.1% on time. The 5pm–8pm window is the weakest at 86.4%, 7 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are August delays on PDX to SLC?
August is the weakest month at 83.9% on time, compared with 92.9% in April. Across the year that is 9 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- SLC to PDX — the return legseparate record
- Portland International (PDX) delay statistics
- Salt Lake City International (SLC) delay statistics
- Delta Air Lines on PDX to SLC90.8%
- SkyWest Airlines on PDX to SLC84.6%
- PDX to SEA, a related route84.9%
- DEN to SLC, a related route78.2%
- PDX to LAX, a related route86.6%
- Alaska Airlines on-time record93.6%
- Delta Air Lines on-time record90.8%
- SkyWest Airlines on-time record84.6%
- The most punctual routes in the US, and the least
- Why the first flight of the morning is statistically safest
Direction matters. PDX to SLC and SLC to PDX are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.