Routes › Salt Lake City (SLC) › SLC to BOI
Route · 12 months to July 2026
Salt Lake City to Boise: on-time record
Salt Lake City International to Boise Air Terminal
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 1,741 flights from Salt Lake City (SLC) to Boise (BOI), a distance of 290 miles. 86.0% of them arrived within 15 minutes of schedule.
That is 10.0 points above the national on-time share of 76.0% for the same period and 2.2 points above the 83.8% recorded for all departures from SLC. Flights that did arrive were 1.1 minutes early on average, and 0.8% 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 91.6% of 523 flights; Delta Air Lines had the lowest at 83.6% of 1,218.
By scheduled departure hour (local time at SLC), flights leaving from 4 pm to 5 pm had the highest on-time share, 90.1%; those leaving from 10 pm to 11 pm had the lowest, 74.7%.
The on-time share is about level with the previous 12 months (86.0%); cancellations moved from 0.2% to 0.8%.
Of the delay minutes that carriers assigned to a BTS cause category on this route, air carrier 66%, late-arriving aircraft 19% and extreme weather 9%.
- On time 86.0%
- Arrived 15+ minutes late 13.2%
- Cancelled 0.8%
- Diverted 0.1%
Airlines on the route compared
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| DL Delta Air Lines | 1,218 | 70% | 83.6% | 0.8 min | 1.1% |
| OO SkyWest Airlines | 523 | 30% | 91.6% | -5.8 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 | SLC to BOI | All departures from SLC | All arrivals at BOI | All reported flights |
|---|---|---|---|---|
| Arrived on time | 86.0% | 83.8% | 80.2% | 76.0% |
| Arrived 15+ minutes late | 13.2% | 15.1% | 19.2% | 21.9% |
| Cancelled | 0.8% | 0.8% | 0.5% | 1.8% |
| Diverted | 0.1% | 0.3% | 0.2% | 0.3% |
| Average arrival delay | -1.1 min | 0.7 min | 3.5 min | 8.1 min |
| Delay minutes per 100 flights | 850 | 1,062 | 1,220 | 1,684 |
| Scheduled flights | 1,741 | 117,896 | 23,707 | 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, BOI to SLC, recorded 90.3% on time across 1,740 flights in the same period.
Month by month
Year on year: on time 86.0% against 86.0% (0.0 pts), cancelled 0.8% against 0.2%, flights 1,741 against 1,658.
By scheduled departure hour
Delay causes
Seasonality
| Calendar month | Flights | On time | Cancelled | Avg arrival delay | Years in sample |
|---|---|---|---|---|---|
| Jan | 380 | 79.5% | 0.8% | 3.1 min | 3 |
| Feb | 340 | 87.9% | 0.0% | -1.9 min | 3 |
| Mar | 429 | 86.9% | 0.0% | -2.1 min | 3 |
| Apr | 432 | 86.8% | 0.2% | -1.1 min | 3 |
| May | 453 | 86.8% | 0.0% | 0.4 min | 3 |
| Jun | 438 | 85.8% | 1.1% | 7.6 min | 3 |
| Jul | 443 | 79.9% | 1.6% | 8.2 min | 3 |
| Aug | 430 | 83.0% | 0.5% | 4.4 min | 3 |
| Sep | 427 | 88.5% | 0.2% | -0.6 min | 3 |
| Oct | 448 | 91.3% | 0.0% | -3.4 min | 3 |
| Nov | 420 | 90.2% | 1.2% | -6.0 min | 3 |
| Dec | 434 | 84.8% | 0.7% | -1.7 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 Salt Lake City (SLC)
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| SLC–DEN | Salt Lake City to Denver | 7,728 | 78.5% | 4.2 min | 0.5% |
| SLC–PHX | Salt Lake City to Phoenix | 5,775 | 83.3% | 2.3 min | 0.5% |
| SLC–LAX | Salt Lake City to Los Angeles | 4,191 | 86.1% | -3.0 min | 0.5% |
| SLC–SEA | Salt Lake City to Seattle | 4,125 | 79.3% | 2.7 min | 0.9% |
| SLC–DFW | Salt Lake City to Dallas/Fort Worth | 3,866 | 76.2% | 9.6 min | 2.4% |
| SLC–LAS | Salt Lake City to Las Vegas | 3,744 | 77.6% | 6.3 min | 0.7% |
| SLC–SFO | Salt Lake City to San Francisco | 3,454 | 65.1% | 15.0 min | 1.0% |
| SLC–ORD | Salt Lake City to Chicago | 3,205 | 74.2% | 12.8 min | 1.5% |
All 95 routes and the airport record for SLC · airport record for BOI
Questions and answers
How often are flights from Salt Lake City to Boise on time?
86.0% of the 1,741 flights scheduled from SLC to BOI 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 SLC to BOI?
Among reporting carriers with at least 60 flights on the route, SkyWest Airlines had the highest on-time share (91.6%), followed by Delta Air Lines (83.6%). Differences of a point or two on a few hundred flights are small.
What causes delays between Salt Lake City and Boise?
For flights that arrived 15 or more minutes late, carriers attributed the delay minutes as follows: air carrier 66%, late-arriving aircraft 19%, extreme weather 9%, national aviation system 7%, 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 SLC?
Flights scheduled to leave SLC from 4 pm to 5 pm arrived on time 90.1% of the time, the highest of any hour with enough flights to compare. The lowest was 10 pm to 11 pm at 74.7%. 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 86.0%, about level with the previous 12 months (86.0%). The monthly chart on this page shows each of the last 36 months. Across those months, October had the highest on-time share (91.3%) and January the lowest (79.5%).
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.