Routes › Boise (BOI) › BOI to SLC
Route · 12 months to July 2026
Boise to Salt Lake City: on-time record
Boise Air Terminal to Salt Lake City International
BTS: A flight is counted as on time if it arrived less than 15 minutes after its scheduled time. Only carriers with at least 0.5 percent of domestic scheduled passenger revenue report. Data through July 2026; this is a monthly history, not live flight status.
In the 12 months to July 2026, reporting carriers scheduled 1,740 flights from Boise (BOI) to Salt Lake City (SLC), a distance of 290 miles. 90.3% of them arrived within 15 minutes of schedule.
That is 14.3 points above the national on-time share of 76.0% for the same period and 7.4 points above the 82.9% recorded for all departures from BOI. Flights that did arrive were 4.6 minutes early on average, and 1.0% of scheduled flights were cancelled (national: 1.8%).
2 reporting carriers flew the route at least 60 times. SkyWest Airlines had the highest on-time share at 94.8% of 522 flights; Delta Air Lines had the lowest at 88.3% of 1,218.
By scheduled departure hour (local time at BOI), flights leaving from 8 am to 9 am had the highest on-time share, 95.9%; those leaving from 1 pm to 2 pm had the lowest, 84.6%.
The on-time share is up 0.5 points on the previous 12 months (89.8%); cancellations moved from 0.2% to 1.0%.
Of the delay minutes that carriers assigned to a BTS cause category on this route, air carrier 58%, late-arriving aircraft 27% and national aviation system 10%.
- On time 90.3%
- Arrived 15+ minutes late 8.6%
- Cancelled 1.0%
- Diverted 0.2%
Airlines on the route compared
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| DL Delta Air Lines | 1,218 | 70% | 88.3% | -1.4 min | 1.3% |
| OO SkyWest Airlines | 522 | 30% | 94.8% | -11.9 min | 0.2% |
Carriers with at least 24 flights in the 12 months to July 2026. The on-time pill is green when a carrier is at or above the route's overall share. Regional carriers operate flights sold under larger airlines' brands; BTS lists the carrier that operated the flight.
Compared with the airports and the nation
| Measure | BOI to SLC | All departures from BOI | All arrivals at SLC | All reported flights |
|---|---|---|---|---|
| Arrived on time | 90.3% | 82.9% | 84.2% | 76.0% |
| Arrived 15+ minutes late | 8.6% | 16.3% | 14.9% | 21.9% |
| Cancelled | 1.0% | 0.5% | 0.8% | 1.8% |
| Diverted | 0.2% | 0.3% | 0.1% | 0.3% |
| Average arrival delay | -4.6 min | 2.5 min | 1.0 min | 8.1 min |
| Delay minutes per 100 flights | 775 | 1,241 | 1,131 | 1,684 |
| Scheduled flights | 1,740 | 23,701 | 117,767 | 7,043,858 |
12 months to July 2026. Delay minutes count late arrivals only (an early arrival is zero), so the per-100-flights row is a normalised total rather than an average of early and late.
The return direction, SLC to BOI, recorded 86.0% on time across 1,741 flights in the same period.
Month by month
Year on year: on time 90.3% against 89.8% (+0.5 pts), cancelled 1.0% against 0.2%, flights 1,740 against 1,657.
By scheduled departure hour
Delay causes
Seasonality
| Calendar month | Flights | On time | Cancelled | Avg arrival delay | Years in sample |
|---|---|---|---|---|---|
| Jan | 380 | 78.7% | 0.8% | 3.8 min | 3 |
| Feb | 340 | 86.5% | 0.0% | -3.2 min | 3 |
| Mar | 428 | 91.1% | 0.0% | -6.9 min | 3 |
| Apr | 432 | 90.3% | 0.2% | -4.1 min | 3 |
| May | 453 | 92.1% | 0.0% | -4.5 min | 3 |
| Jun | 438 | 88.8% | 1.4% | 2.5 min | 3 |
| Jul | 442 | 86.7% | 1.4% | 2.5 min | 3 |
| Aug | 430 | 87.2% | 0.5% | 1.0 min | 3 |
| Sep | 427 | 91.1% | 0.2% | -3.3 min | 3 |
| Oct | 448 | 92.6% | 0.0% | -5.8 min | 3 |
| Nov | 420 | 92.1% | 1.4% | -6.8 min | 3 |
| Dec | 434 | 87.8% | 0.9% | -5.5 min | 3 |
Each calendar month summed across the 36 months on file, so most rows combine three years. The pill compares the month with the route's own 12-month share.
Other routes from Boise (BOI)
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| BOI–SEA | Boise to Seattle | 3,761 | 84.8% | -2.5 min | 0.4% |
| BOI–DEN | Boise to Denver | 3,033 | 81.2% | 5.7 min | 0.1% |
| BOI–PHX | Boise to Phoenix | 2,014 | 83.1% | 3.1 min | 0.4% |
| BOI–SFO | Boise to San Francisco | 1,716 | 67.8% | 17.2 min | 0.5% |
| BOI–LAX | Boise to Los Angeles | 1,373 | 92.6% | -5.7 min | 0.2% |
| BOI–LAS | Boise to Las Vegas | 1,363 | 80.9% | 3.6 min | 0.2% |
| BOI–ORD | Boise to Chicago | 1,111 | 73.8% | 13.0 min | 1.2% |
| BOI–PDX | Boise to Portland | 1,084 | 90.9% | -3.4 min | 0.6% |
All 25 routes and the airport record for BOI · airport record for SLC
Questions and answers
How often are flights from Boise to Salt Lake City on time?
90.3% of the 1,740 flights scheduled from BOI to SLC in the 12 months to July 2026 arrived less than 15 minutes after their scheduled time. The national share for the same period was 76.0%. Cancelled and diverted flights count as not on time.
Which airline has the highest on-time share from BOI to SLC?
Among reporting carriers with at least 60 flights on the route, SkyWest Airlines had the highest on-time share (94.8%), followed by Delta Air Lines (88.3%). Differences of a point or two on a few hundred flights are small.
What causes delays between Boise and Salt Lake City?
For flights that arrived 15 or more minutes late, carriers attributed the delay minutes as follows: air carrier 58%, late-arriving aircraft 27%, national aviation system 10%, extreme weather 5%, security 0%. The categories are the carriers' own reports to BTS; weather that slows the wider system is usually recorded under the National Aviation System rather than extreme weather.
What time of day has the highest on-time share from BOI?
Flights scheduled to leave BOI from 8 am to 9 am arrived on time 95.9% of the time, the highest of any hour with enough flights to compare. The lowest was 1 pm to 2 pm at 84.6%. Delays tend to build through the day as late aircraft carry over to later flights.
Is it getting better?
The on-time share for the 12 months to July 2026 was 90.3%, up 0.5 points on the previous 12 months (89.8%). The monthly chart on this page shows each of the last 36 months. Across those months, October had the highest on-time share (92.6%) and January the lowest (78.7%).
Where does this data come from?
Every figure is computed from the Bureau of Transportation Statistics Reporting Carrier On-Time Performance files, which list each scheduled domestic flight by the carriers required to report. This page covers August 2023 to July 2026. It shows totals and averages only; it is not a live flight-status service.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (1987 to present), monthly files August 2023 to July 2026, a US government work in the public domain. Figures are totals and averages over all scheduled flights by reporting carriers on the route; no individual flight or aircraft is identified. Times are local to the departure airport. The load factor and passenger counts from the BTS T-100 series are not included in this edition. See the methodology; report processing errors through corrections.