Carrier route record
DLGEG→SLC
Delta Air Lines · Spokane to Salt Lake City
- Flights
- 927
- Period
- July 2025 to June 2026
- Share of route
- 56%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on GEG to SLC 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 11 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 927 flights, with a median arrival 12 minutes early.
Set against the rest of the country, Delta's GEG to SLC record is 11 points better than the US average of 77.6%. That gap is worth roughly 105 fewer late arrivals for every thousand flights.
Key figures
On time
88.1%
Arrivals under 15 minutes late, of 918 completed flights
Avg delay
91 min
Across delayed arrivals only, not all flights
Cancelled
0.86%
National rate is 1.81%
Whole route
90.6%
Every carrier on GEG to SLC, 1,666 flights
These figures cover 927 flights between July 2025 and June 2026. The median arrival is 12 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 GEG to SLC
Delta flew 927 of the 1,666 flights on GEG to SLC, most of the route. Its 88.1% on time is 3 points worse than the route as a whole, which runs 90.6%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 93.7% to Delta at 88.1%.
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 |
|---|---|---|---|---|---|
| SkyWest Airlines | 739 | 93.7% | 72 min | 0.41% | A+ |
| Delta Air Lines (this page) | 927 | 88.1% | 91 min | 0.86% | A+ |
Flight by flight
Delta flight numbers on GEG to SLC
Departure window
When Delta runs best on this route
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 927 flights.
- 5am–8am365 flights92.0%
- 8am–11am12 flights—
- 11am–2pm304 flights86.1%
- 2pm–5pm97 flights85.1%
- 5pm–8pm149 flights84.5%
- 8pm–5am—
Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 92.0% on time for the 5am–8am window against 84.5% for 5pm–8pm. Worth taking if the schedule allows, not worth an extra connection. The 5am–8am window is the busiest, with 365 flights scheduled in it.
Across the year
Delta on GEG to SLC through the year
August is the worst month at 77.6% on time, 16 points below April, the best at 93.2%. 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. June was the busiest month here, with 108 flights.
Across the week, Thursday is the strongest day at 92.2% on time and Friday the weakest at 84.8%. 7 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 52% of the 9,921 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
- 44%Carrier
- 4%National Airspace System
- 1%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 9,921 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 9,921 reported delay minutes.
The largest share of delay minutes, 44%, 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 4,324 of the 9,921 delay minutes reported here.
Cancellations are rare at 0.86%, 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 4.6% 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 546 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 81.8% on time across 927 flights, 6 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 6 points of difference.
One caution: this is a thin sample. 927 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 Delta on GEG to SLC
Put together: treat all of this as provisional. 927 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 88.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 918 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.