Carrier route record
DLMSO→SLC
Delta Air Lines · Missoula to Salt Lake City
- Flights
- 467
- Period
- July 2025 to June 2026
- Share of route
- 44%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on MSO to SLC 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 12 points better than the national rate of 77.6%. When something does go wrong the average delay runs close to two hours. That rests on 467 flights, with a median arrival 14 minutes early.
Set against the rest of the country, Delta's MSO to SLC record is 12 points better than the US average of 77.6%. That gap is worth roughly 123 fewer late arrivals for every thousand flights.
Key figures
On time
89.9%
Arrivals under 15 minutes late, of 464 completed flights
Avg delay
122 min
Across delayed arrivals only, not all flights
Cancelled
0.43%
National rate is 1.81%
Whole route
90.9%
Every carrier on MSO to SLC, 1,059 flights
These figures cover 467 flights between July 2025 and June 2026. The median arrival is 14 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 MSO to SLC
Delta flew 467 of the 1,059 flights on MSO to SLC, about 44% of it. Its 89.9% on time is about level with the route as a whole at 90.9%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 91.8% to Delta 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 |
|---|---|---|---|---|---|
| SkyWest Airlines | 592 | 91.8% | 47 min | 1.35% | A |
| Delta Air Lines (this page) | 467 | 89.9% | 122 min | 0.43% | A+ |
Flight by flight
Delta flight numbers on MSO 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 467 flights.
- 5am–8am360 flights90.5%
- 8am–11am—
- 11am–2pm104 flights87.3%
- 2pm–5pm3 flights—
- 5pm–8pm—
- 8pm–5am—
Scale runs 80% to 95%. Rows with fewer than 30 flights show a dash.
The 5am–8am window is the strongest at 90.5% on time. The full set of windows spans 3 points.
Across the year
Delta on MSO to SLC through the year
Delays peak in March, when the on-time rate falls to 81.7%. June is the strongest month at 100.0%. Moving a flexible trip across that boundary buys 18 points. March was the busiest month here, with 62 flights.
Across the week, Monday is the strongest day at 95.5% on time and Thursday the weakest at 83.3%. 12 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 59% of the 5,737 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.
- 59%Carrier
- 25%Late-arriving aircraft
- 10%Extreme weather
- 6%National Airspace System
The largest share of delay minutes, 59%, 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 3,405 of the 5,737 delay minutes reported here. The split is drawn from 5,737 reported delay minutes.
Cancellations are rare at 0.43%, 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 3.9% 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 436 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 83.9% on time across 467 flights, 6 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 6 points of difference.
One caution: this is a thin sample. 467 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 MSO to SLC
Put together: treat all of this as provisional. 467 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 89.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 464 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.