Carrier route record
DLGEG→SLC
Delta Air Lines · Spokane to Salt Lake City
- Flights
- 974
- Period
- September 2025 to August 2026
- Share of route
- 58%
- Carriers
- 2
Historical statistics for September 2025 to August 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 77.3%. When something does go wrong the average delay runs an hour and a half. That rests on 974 flights, with a median arrival 13 minutes early.
Set against the rest of the country, Delta's GEG to SLC record is 11 points better than the US average of 77.3%. That gap is worth roughly 105 fewer late arrivals for every thousand flights.
Key figures
On time
87.8%
Arrivals under 15 minutes late, of 966 completed flights
Avg delay
83 min
Across delayed arrivals only, not all flights
Cancelled
0.72%
National rate is 1.89%
Whole route
90.4%
Every carrier on GEG to SLC, 1,668 flights
These figures cover 974 flights between September 2025 and August 2026. The median arrival is 13 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
Delta against every carrier on GEG to SLC
Delta flew 974 of the 1,668 flights on GEG to SLC, most of the route. Its 87.8% on time is 3 points worse than the route as a whole, which runs 90.4%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 94.1% to Delta at 87.8%.
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 | 694 | 94.1% | 73 min | 0.43% | A+ |
| Delta Air Lines (this page) | 974 | 87.8% | 83 min | 0.72% | A+ |
Flight by flight
Delta flight numbers on GEG to SLC
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 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 974 flights.
- 5am–8am365 flights92.5%
- 8am–11am12 flights—
- 11am–2pm304 flights84.5%
- 2pm–5pm97 flights85.1%
- 5pm–8pm196 flights85.1%
- 8pm–5am—
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 84.5% on time against 92.5% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. 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 79.8% on time, 13 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. July was the busiest month here, with 118 flights.
Across the week, Thursday is the strongest day at 92.1% on time and Saturday the weakest at 81.8%, a spread of 10 points.
Arrival by arrival
How late Delta on GEG to SLC runs when it is late
Delta on GEG to SLC often beats the schedule: 437 of 966 completed flights, 45%, arrived 15 minutes or more early. The 118 late arrivals split 38 under half an hour, 39 between 30 and 60 minutes, and 41 an hour or more.
- 15+ min early437 flights45.2%
- Within 15 min411 flights42.5%
- 15–29 min late38 flights3.9%
- 30–59 min late39 flights4.0%
- 1–2 hours late22 flights2.3%
- 2+ hours late19 flights2.0%
Scale runs 0% to 100%.
Share of 966 completed flights by arrival against schedule.
25 of 136 late departures made up the time and arrived on time, 18% of them. Only 7 left on time and still arrived late.
The worst days
Worst days for Delta on GEG to SLC
The latest arrival of the period was on 5 November 2025, 10 hours 26 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 5 November 2025 | 10 hours 26 minutes | Carrier |
| 7 June 2026 | 8 hours 38 minutes | Carrier |
| 20 September 2025 | 8 hours 6 minutes | Late-arriving aircraft |
| 26 January 2026 | 8 hours 2 minutes | Carrier |
| 7 July 2026 | 7 hours 51 minutes | Carrier |
Delay causes
Why Delta runs late on this route
Late-arriving aircraft accounts for 54% of the 9,781 delay minutes carriers reported here, and the remaining four split what is left.
- 54%Late-arriving aircraft
- 41%Carrier
- 4%National Airspace System
- 1%Extreme weather
54% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 9,781 reported delay minutes here, that single category outweighs weather by 53 to one. The split is drawn from 9,781 reported delay minutes.
The largest share of delay minutes, 41%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 4,026 of the 9,781 delay minutes reported here.
Cancellations are rare at 0.72%, 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 4.2% 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 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.
The return leg is a different operation and performs like one: it runs 81.1% on time across 974 flights, 7 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 7 points of difference.
One caution: this is a thin sample. 974 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. 974 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 87.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 966 completed flights over 12 months sit behind that.
Related
Where to go next
- GEG to SLC, every carrier
- Delta on SLC to GEG, the return leg
- SkyWest Airlines on GEG to SLC94.1%
- Delta Air Lines network-wide record
- Salt Lake City International (SLC) 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.