Carrier route record
DLBIL→SLC
Delta Air Lines · Billings to Salt Lake City
- Flights
- 366
- Period
- July 2025 to June 2026
- Share of route
- 34%
- Carriers
- 2
Historical statistics for July 2025 to June 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 16 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 366 flights, with a median arrival 18 minutes early.
Set against the rest of the country, Delta's BIL to SLC record is 16 points better than the US average of 77.6%. That gap is worth roughly 155 fewer late arrivals for every thousand flights.
Key figures
On time
93.1%
Arrivals under 15 minutes late, of 364 completed flights
Avg delay
97 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.81%
Whole route
91.6%
Every carrier on BIL to SLC, 1,074 flights
These figures cover 366 flights between July 2025 and June 2026. The median arrival is 18 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
Delta against every carrier on BIL to SLC
Delta flew 366 of the 1,074 flights on BIL to SLC, about 34% of it. Its 93.1% on time is 2 points better than the route as a whole, which runs 91.6%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Delta at 93.1% to SkyWest at 90.7%.
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 |
|---|---|---|---|---|---|
| Delta Air Lines (this page) | 366 | 93.1% | 97 min | 0.55% | A+ |
| SkyWest Airlines | 708 | 90.7% | 79 min | 0.71% | A+ |
Flight by flight
Delta flight numbers on BIL to SLC
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 366 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 93.1% 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. August was the busiest month here, with 32 flights.
Across the week, Wednesday is the strongest day at 96.2% on time and Sunday the weakest at 90.4%. 6 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta runs late on this route
One category carries most of the weight here. Carrier accounts for 73% of the 2,419 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.
- 73%Carrier
- 18%National Airspace System
- 9%Late-arriving aircraft
The largest share of delay minutes, 73%, 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 1,768 of the 2,419 delay minutes reported here. The split is drawn from 2,419 reported delay minutes.
Cancellations are rare at 0.55%, 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 3.0% 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 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 81.6% on time across 366 flights, 12 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 12 points of difference.
One caution: this is a thin sample. 366 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. 366 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 93.1% 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.