Carrier route record
OOSLC→BOI
SkyWest Airlines · Salt Lake City to Boise
- Flights
- 513
- Period
- September 2025 to August 2026
- Share of route
- 30%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with SkyWest Airlines.
SkyWest on SLC to BOI 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 15 points better than the national rate of 77.3%. When something does go wrong the average delay runs about 55 minutes. That rests on 513 flights, with a median arrival 11 minutes early.
Set against the rest of the country, SkyWest's SLC to BOI record is 15 points better than the US average of 77.3%. That gap is worth roughly 145 fewer late arrivals for every thousand flights.
Key figures
On time
91.8%
Arrivals under 15 minutes late, of 511 completed flights
Avg delay
54 min
Across delayed arrivals only, not all flights
Cancelled
0.19%
National rate is 1.89%
Whole route
86.3%
Every carrier on SLC to BOI, 1,732 flights
These figures cover 513 flights between September 2025 and August 2026. The median arrival is 11 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
SkyWest against every carrier on SLC to BOI
SkyWest flew 513 of the 1,732 flights on SLC to BOI, about 30% of it. Its 91.8% on time is 6 points better than the route as a whole, which runs 86.3%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from SkyWest at 91.8% to Delta at 84.0%.
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 (this page) | 513 | 91.8% | 54 min | 0.19% | A+ |
| Delta Air Lines | 1,219 | 84.0% | 61 min | 1.07% | B |
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 SkyWest 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 513 flights.
- 5am–8am—
- 8am–11am68 flights97.0%
- 11am–2pm6 flights—
- 2pm–5pm206 flights93.2%
- 5pm–8pm14 flights—
- 8pm–5am219 flights89.5%
Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 97.0% on time for the 8am–11am window against 89.5% for 8pm–5am. Worth taking if the schedule allows, not worth an extra connection. The 8pm–5am window is the busiest, with 219 flights scheduled in it.
Across the year
SkyWest on SLC to BOI through the year
July is the worst month at 77.4% on time, 20 points below January, the best at 97.3%. 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. December was the busiest month here, with 66 flights.
Across the week, Monday is the strongest day at 95.8% on time and Sunday the weakest at 87.2%, a spread of 9 points.
Arrival by arrival
How late SkyWest on SLC to BOI runs when it is late
SkyWest on SLC to BOI often beats the schedule: 176 of 511 completed flights, 34%, arrived 15 minutes or more early. The 42 late arrivals split 18 under half an hour, 11 between 30 and 60 minutes, and 13 an hour or more.
- 15+ min early176 flights34.4%
- Within 15 min293 flights57.3%
- 15–29 min late18 flights3.5%
- 30–59 min late11 flights2.2%
- 1–2 hours late9 flights1.8%
- 2+ hours late4 flights0.8%
Scale runs 0% to 100%.
Share of 511 completed flights by arrival against schedule.
14 of 50 late departures made up the time and arrived on time, 28% of them. Only 6 left on time and still arrived late.
The worst days
Worst days for SkyWest on SLC to BOI
The latest arrival of the period was on 13 June 2026, 3 hours 18 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 June 2026 | 3 hours 18 minutes | Carrier |
| 15 July 2026 | 3 hours 2 minutes | Extreme weather |
| 27 March 2026 | 3 hours 1 minute | Carrier |
| 9 August 2026 | 2 hours 39 minutes | Carrier |
| 18 February 2026 | 1 hour 49 minutes | Extreme weather |
Delay causes
Why SkyWest runs late on this route
Carrier accounts for 66% of the 2,279 delay minutes carriers reported here, and the remaining four split what is left.
- 66%Carrier
- 27%Extreme weather
- 6%National Airspace System
Extreme weather accounts for 27% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 4.6 times the usual weather exposure. The split is drawn from 2,279 reported delay minutes.
The largest share of delay minutes, 66%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,514 of the 2,279 delay minutes reported here.
Cancellations are rare at 0.19%, 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 2.5% 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.
At 290 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 94.9% on time across 513 flights, 3 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 3 points of difference.
One caution: this is a thin sample. 513 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 SkyWest on SLC to BOI
Put together: treat all of this as provisional. 513 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 91.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 511 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.