Carrier route record
DLBIL→SLC
Delta Air Lines · Billings to Salt Lake City
- Flights
- 365
- Period
- September 2025 to August 2026
- Share of route
- 34%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on BIL to SLC earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 17 points better than the national rate of 77.3%. When something does go wrong the average delay runs an hour and a half. That rests on 365 flights, with a median arrival 17 minutes early.
Set against the rest of the country, Delta's BIL to SLC record is 17 points better than the US average of 77.3%. That gap is worth roughly 167 fewer late arrivals for every thousand flights.
Key figures
On time
94.0%
Arrivals under 15 minutes late, of 364 completed flights
Avg delay
98 min
Across delayed arrivals only, not all flights
Cancelled
0.27%
National rate is 1.89%
Whole route
91.3%
Every carrier on BIL to SLC, 1,074 flights
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 17 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.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
Delta against every carrier on BIL to SLC
Delta flew 365 of the 1,074 flights on BIL to SLC, about 34% of it. Its 94.0% on time is 3 points better than the route as a whole, which runs 91.3%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Delta at 94.0% to SkyWest at 89.9%.
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 |
|---|---|---|---|---|---|
| Delta Air Lines (this page) | 365 | 94.0% | 98 min | 0.27% | A+ |
| SkyWest Airlines | 709 | 89.9% | 84 min | 0.71% | A+ |
Flight by flight
Delta flight numbers on BIL to SLC
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 365 flights.
There are not enough flights in each departure window to split Delta's BIL to SLC record by time of day without the percentages moving on noise. The headline rate of 94.0% is the reliable figure here.
Across the year
Delta on BIL to SLC through the year
December is the weak month at 80.6% on time, against 100.0% in May. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. January was the busiest month here, with 31 flights.
Across the week, Wednesday is the strongest day at 98.1% on time and Tuesday the weakest at 90.4%, a spread of 8 points.
Arrival by arrival
How late Delta on BIL to SLC runs when it is late
Delta on BIL to SLC often beats the schedule: 223 of 364 completed flights, 61%, arrived 15 minutes or more early. The 22 late arrivals split 5 under half an hour, 7 between 30 and 60 minutes, and 10 an hour or more.
- 15+ min early223 flights61.3%
- Within 15 min119 flights32.7%
- 15–29 min late5 flights1.4%
- 30–59 min late7 flights1.9%
- 1–2 hours late4 flights1.1%
- 2+ hours late6 flights1.6%
Scale runs 0% to 100%.
Share of 364 completed flights by arrival against schedule.
Only 13 of 364 completed flights left 15 minutes late or more, too few to say how often the time is made up.
The worst days
Worst days for Delta on BIL to SLC
The latest arrival of the period was on 6 July 2026, 6 hours 59 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 6 July 2026 | 6 hours 59 minutes | Carrier |
| 14 October 2025 | 6 hours 3 minutes | Carrier |
| 19 February 2026 | 3 hours 48 minutes | Carrier |
| 28 October 2025 | 3 hours 34 minutes | Late-arriving aircraft |
| 13 December 2025 | 2 hours 4 minutes | Carrier |
Delay causes
Why Delta runs late on this route
Carrier accounts for 70% of the 2,163 delay minutes carriers reported here, and the remaining four split what is left.
- 70%Carrier
- 20%National Airspace System
- 10%Late-arriving aircraft
The largest share of delay minutes, 70%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,512 of the 2,163 delay minutes reported here. The split is drawn from 2,163 reported delay minutes.
Cancellations are rare at 0.27%, 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 2.7% 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 387 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 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 79.7% on time across 365 flights, 14 points below 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 14 points of difference.
One caution: this is a thin sample. 365 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 BIL to SLC
Put together: treat all of this as provisional. 365 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 94.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 364 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.