Carrier route record
OOSLC→BOI
SkyWest Airlines · Salt Lake City to Boise
- Flights
- 519
- Period
- July 2025 to June 2026
- Share of route
- 30%
- Carriers
- 2
Historical statistics for July 2025 to June 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 77.6%. When something does go wrong the average delay runs about 50 minutes. That rests on 519 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 77.6%. That gap is worth roughly 150 fewer late arrivals for every thousand flights.
Key figures
On time
92.6%
Arrivals under 15 minutes late, of 517 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
0.19%
National rate is 1.81%
Whole route
87.1%
Every carrier on SLC to BOI, 1,742 flights
These figures cover 519 flights between July 2025 and June 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.
Carrier by carrier
SkyWest against every carrier on SLC to BOI
SkyWest flew 519 of the 1,742 flights on SLC to BOI, about 30% of it. Its 92.6% on time is 6 points better than the route as a whole, which runs 87.1%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from SkyWest at 92.6% to Delta at 84.7%.
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) | 519 | 92.6% | 50 min | 0.19% | A+ |
| Delta Air Lines | 1,223 | 84.7% | 59 min | 1.06% | B |
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 519 flights.
- 5am–8am—
- 8am–11am71 flights97.1%
- 11am–2pm6 flights—
- 2pm–5pm205 flights93.6%
- 5pm–8pm10 flights—
- 8pm–5am227 flights90.7%
Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.
The early departures do better, though not dramatically: 97.1% on time for the 8am–11am window against 90.7% for 8pm–5am. Worth taking if the schedule allows, not worth an extra connection. The 8pm–5am window is the busiest, with 227 flights scheduled in it.
Across the year
SkyWest on SLC to BOI through the year
Delays peak in May, when the on-time rate falls to 87.5%. January is the strongest month at 97.3%. Moving a flexible trip across that boundary buys 10 points. December was the busiest month here, with 66 flights.
Across the week, Saturday is the strongest day at 96.5% on time and Wednesday the weakest at 88.2%. 8 points is a smaller lever than departure hour, but it is free.
Delay causes
Why SkyWest runs late on this route
One category carries most of the weight here. Carrier accounts for 77% of the 1,880 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.
- 77%Carrier
- 18%Extreme weather
- 5%National Airspace System
Extreme weather accounts for 18% 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 2.8 times the usual weather exposure. The split is drawn from 1,880 reported delay minutes.
The largest share of delay minutes, 77%, 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 1,456 of the 1,880 delay minutes reported here.
Cancellations are rare at 0.19%, 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 2.1% 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.
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 runs 95.3% on time across 517 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 519 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. 519 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 92.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 517 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.