Carrier route record
DLSLC→GEG
Delta Air Lines · Salt Lake City to Spokane
- 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 SLC to GEG lands a B+, 4 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 974 flights, with a median arrival 7 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Delta on SLC to GEG from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
81.1%
Arrivals under 15 minutes late, of 966 completed flights
Avg delay
72 min
Across delayed arrivals only, not all flights
Cancelled
0.62%
National rate is 1.89%
Whole route
85.9%
Every carrier on SLC to GEG, 1,668 flights
These figures cover 974 flights between September 2025 and August 2026. The median arrival is 7 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 SLC to GEG
Delta flew 974 of the 1,668 flights on SLC to GEG, most of the route. Its 81.1% on time is 5 points worse than the route as a whole, which runs 85.9%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 92.7% to Delta at 81.1%.
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 | 694 | 92.7% | 57 min | 0.14% | A+ |
| Delta Air Lines (this page) | 974 | 81.1% | 72 min | 0.62% | B+ |
Flight by flight
Delta flight numbers on SLC to GEG
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–8am—
- 8am–11am12 flights—
- 11am–2pm338 flights81.8%
- 2pm–5pm200 flights79.3%
- 5pm–8pm60 flights80.0%
- 8pm–5am364 flights81.4%
Scale runs 70% to 85%. Rows with fewer than 30 flights show a dash.
The overnight block holds up unusually well at 81.4% on time across 364 flights. Red-eyes fly into empty airspace and empty gates, and they are the first rotation of the aircraft's day rather than the last. The 8pm–5am window is the busiest, with 364 flights scheduled in it.
Across the year
Delta on SLC to GEG through the year
July is the worst month at 72.9% on time, 17 points below March, the best at 90.3%. 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, Wednesday is the strongest day at 88.6% on time and Sunday the weakest at 75.5%, a spread of 13 points.
Arrival by arrival
How late Delta on SLC to GEG runs when it is late
Delta on SLC to GEG often beats the schedule: 270 of 966 completed flights, 28%, arrived 15 minutes or more early. The 183 late arrivals split 63 under half an hour, 70 between 30 and 60 minutes, and 50 an hour or more.
- 15+ min early270 flights28.0%
- Within 15 min513 flights53.1%
- 15–29 min late63 flights6.5%
- 30–59 min late70 flights7.2%
- 1–2 hours late31 flights3.2%
- 2+ hours late19 flights2.0%
Scale runs 0% to 100%.
Share of 966 completed flights by arrival against schedule.
38 of 177 late departures made up the time and arrived on time, 21% of them. 44 flights left on time and still arrived late.
The worst days
Worst days for Delta on SLC to GEG
The latest arrival of the period was on 19 September 2025, 13 hours 26 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 19 September 2025 | 13 hours 26 minutes | Carrier |
| 25 January 2026 | 12 hours 59 minutes | Carrier |
| 11 June 2026 | 10 hours 1 minute | Carrier |
| 1 September 2025 | 8 hours 57 minutes | Carrier |
| 29 January 2026 | 8 hours 26 minutes | Carrier |
Delay causes
Why Delta runs late on this route
Carrier accounts for 64% of the 13,000 delay minutes carriers reported here, and the remaining four split what is left.
- 64%Carrier
- 15%National Airspace System
- 14%Late-arriving aircraft
- 8%Extreme weather
The largest share of delay minutes, 64%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 8,469 of the 13,000 delay minutes reported here. The split is drawn from 13,252 reported delay minutes.
Cancellations are rare at 0.62%, 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
5.2% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
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 87.8% on time across 974 flights, 7 points above 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 SLC to GEG
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 81.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 966 completed flights over 12 months sit behind that.
Related
Where to go next
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.