Carrier route record
DLSLC→MSO
Delta Air Lines · Salt Lake City to Missoula
- 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 SLC to MSO lands a B+, 6 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 467 flights, with a median arrival 7 minutes early.
Set against the rest of the country, Delta's SLC to MSO record is 6 points better than the US average of 77.6%. That gap is worth roughly 63 fewer late arrivals for every thousand flights.
Key figures
On time
83.9%
Arrivals under 15 minutes late, of 465 completed flights
Avg delay
97 min
Across delayed arrivals only, not all flights
Cancelled
0.43%
National rate is 1.81%
Whole route
88.7%
Every carrier on SLC to MSO, 1,059 flights
These figures cover 467 flights between July 2025 and June 2026. The median arrival is 7 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 SLC to MSO
Delta flew 467 of the 1,059 flights on SLC to MSO, about 44% of it. Its 83.9% on time is 5 points worse than the route as a whole, which runs 88.7%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from SkyWest at 92.6% to Delta at 83.9%.
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 | 92.6% | 39 min | 1.35% | A |
| Delta Air Lines (this page) | 467 | 83.9% | 97 min | 0.43% | B+ |
Flight by flight
Delta flight numbers on SLC to MSO
Departure window
When Delta runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 14 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am60 flights81.4%
- 11am–2pm47 flights95.7%
- 2pm–5pm2 flights—
- 5pm–8pm—
- 8pm–5am358 flights82.6%
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 11am–2pm slot at 95.7% on time, ahead of 8am–11am at 81.4%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 8pm–5am window is the busiest, with 358 flights scheduled in it.
Across the year
Delta on SLC to MSO through the year
July is the worst month at 74.2% on time, 20 points below May, the best at 94.6%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. March was the busiest month here, with 62 flights.
Across the week, Saturday is the strongest day at 92.2% on time and Wednesday the weakest at 68.7%. 24 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 68% of the 7,270 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.
- 68%Carrier
- 13%Extreme weather
- 11%Late-arriving aircraft
- 8%National Airspace System
Extreme weather accounts for 13% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.0 times the usual weather exposure. The split is drawn from 7,270 reported delay minutes.
The largest share of delay minutes, 68%, 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 4,967 of the 7,270 delay minutes reported here.
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
6.0% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last an hour and a half, which a normal layover absorbs.
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 11am–2pm window matters as much as it does.
The return leg is a different operation and performs like one: it runs 89.9% on time across 467 flights, 6 points above 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 SLC to MSO
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 83.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 465 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.