Route reliability record
SLC→MSO
Salt Lake City to Missoula
- Flights
- 1,059
- Period
- September 2025 to August 2026
- Distance
- 436 mi
- Carriers
- 2
This route 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 11 points better than the national rate of 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 1,059 SLC to MSO flights, of which SkyWest Airlines flew 592 at 91.7% on time.
Best time to fly SLC to MSO: a 11am–2pm departure, ideally on a Tuesday. Flights in that window arrived on time 94.4% of the time and Tuesday flights 92.2%, against 88.7% for the route overall.
Set against the rest of the country, this route's record is 11 points better than the US average of 77.3%. That gap is worth roughly 114 fewer late arrivals for every thousand flights.
Key figures
On time
88.7%
Arrivals under 15 minutes late, of 1,046 completed flights
Avg delay
68 min
Across delayed arrivals only, not all flights
Cancelled
0.94%
National rate is 1.89%
Best carrier
SkyWest
91.7% on time across 592 flights
These figures cover 1,059 flights between September 2025 and August 2026. The median arrival is 9 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.
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Carrier by carrier
Which airline is most reliable on SLC to MSO
The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 91.7% of the time; Delta Air Lines manages 84.9%. Sample sizes sit next to every figure, because a two-point gap across 467 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 592 | 91.7% | 44 min | 1.35% | A |
| Delta Air Lines | 467 | 84.9% | 85 min | 0.43% | B+ |
SkyWest leads Delta by 7 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Flights on SLC to MSO
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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Best ways to make this trip
The most reliable ways to fly Salt Lake City to Missoula
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. SLC → MSOSalt Lake City to Missoula | SkyWest Airlines | 90.5% | 91.7% | 1.35% | 8am–11am, Tue | OO 4112 10:45 |
| 2. SLC → MSOSalt Lake City to Missoula | Delta Air Lines | 84.5% | 84.9% | 0.43% | 11am–2pm, Sat | DL 1723 22:45 |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 10 points, against 7 points between the best and worst carrier.
- 5am–8am—
- 8am–11am199 flights90.5%
- 11am–2pm160 flights94.4%
- 2pm–5pm342 flights90.0%
- 5pm–8pm—
- 8pm–5am358 flights84.0%
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 94.4% on time, ahead of 8pm–5am at 84.0%. 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.
Explore
Filter SLC to MSO by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On SLC to MSO, the best departure window is 11am–2pm at 94.4% on time and the worst is 8pm–5am at 84.0%, a wide gap of 10.4 points. All US flights leaving 11am–2pm ran 78.3%.
- 5–8am—
- 8–11am90.5%
- 11am–2pm94.4%
- 2–5pm90.0%
- 5–8pm—
- 8pm–5am84.0%
best all US flightsScale 60% to 100%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 15 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
Delays peak in April, when the on-time rate falls to 82.0%. June is the strongest month at 96.7%. Moving a flexible trip across that boundary buys 15 points. May was the busiest month here, with 93 flights.
Across the week, Tuesday is the strongest day at 92.2% on time and Wednesday the weakest at 81.5%, a spread of 11 points.
Delay causes
Why this route gets delayed
Carrier accounts for 66% of the 8,044 delay minutes carriers reported here, and the remaining four split what is left.
- 66%Carrier
- 20%Extreme weather
- 8%Late-arriving aircraft
- 6%National Airspace System
Extreme weather accounts for 20% 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 3.4 times the usual weather exposure. The split is drawn from 8,044 reported delay minutes.
The largest share of delay minutes, 66%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 5,300 of the 8,044 delay minutes reported here.
Cancellations sit at 0.94% against a national 1.89%, which is ordinary. Diversions add another 0.28%.
Connections and stage length
What a delay here actually costs
Badly late arrivals are rare here: only 3.3% 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 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 runs 91.2% on time across 1,059 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 1,059 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.
Work out the risk of missing a connection in MSO after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 1,059 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 88.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 1,046 completed flights over 12 months sit behind that.
Common questions
SLC to MSO questions
How often is SLC to MSO delayed?
About one flight in nine arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 11.3% of the 1,059 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on SLC to MSO?
SkyWest Airlines leads at 91.7% on time across 592 flights. Delta Air Lines is at the other end on 84.9%, a gap of 7 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on SLC to MSO?
The 11am–2pm departure window is the strongest at 94.4% on time. The 8pm–5am window is the weakest at 84.0%, 10 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are April delays on SLC to MSO?
April is the weakest month at 82.0% on time, compared with 96.7% in June. Across the year that is 15 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- MSO to SLC — the return legseparate record
- Salt Lake City International (SLC) delay statistics
- SkyWest Airlines on SLC to MSO91.7%
- Delta Air Lines on SLC to MSO84.9%
- SLC to DEN, a related route79.0%
- DEN to MSO, a related route81.5%
- SLC to PHX, a related route83.5%
- SkyWest Airlines on-time record91.7%
- Delta Air Lines on-time record84.9%
- The most punctual routes in the US, and the least
- The best time of day to fly, according to 7.05 million flight records
Direction matters. SLC to MSO and MSO to SLC are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.