78% of flights from Salt Lake City to Denver arrived on time over the past 12 months. That is about the typical U.S. route. The 5 a.m. departures ran on time 95% of the time; the 3 p.m. ones 58%. Most reliable airline: United Airlines (83%). 7% of flights arrived more than an hour late or not at all.
How late?
The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for SLC → DEN: when a flight was late, it was under 45 minutes late 60% of the time. About 1 in 16 flights landed an hour or more late, and 1 in 91 three hours or more; 0.5% were cancelled outright.
- On time or early78%
- 15–30 min late8.4%
- 30–60 min late6.3%
- 1–2 hours late3.8%
- 2–3 hours late1.2%
- 3+ hours late1.1%
- Diverted0.3%
- Cancelled0.5%
Share of all 7,709 scheduled flights, past 12 months, by arrival time against schedule.
By airline
| Airline | Flights | On time | Cancelled | Typical arrival | 1h+ late | Avg when late | Operated by |
|---|---|---|---|---|---|---|---|
| United Airlines | 2,696 | 83% | 0.5% | −9 min | 5.3% | +67 min | SkyWest 51%, United Airlines 49% |
| Southwest Airlines | 2,283 | 72% | 0.6% | −2 min | 5.9% | +49 min | Southwest Airlines |
| Delta Air Lines | 1,697 | 79% | 0.2% | −8 min | 7.1% | +64 min | Delta Air Lines |
| Frontier Airlines | 1,033 | 79% | 0.9% | −11 min | 7.1% | +79 min | Frontier Airlines |
Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.
Best time of day to fly
On-time rate by scheduled departure hour (local time at SLC). Delays build through the day as late planes knock on, so early flights usually do best.
By airline and hour
| Departs | United Airlines | Southwest Airlines | Delta Air Lines | Frontier Airlines |
|---|---|---|---|---|
| 5 a.m. | 94% | 97% | — | — |
| 6 a.m. | — | 93% | — | 91% |
| 7 a.m. | 92% | 90% | 85% | 89% |
| 8 a.m. | 83% | 52% | — | 70% |
| 10 a.m. | 85% | 68% | 77% | — |
| 11 a.m. | — | 79% | — | — |
| noon | — | 83% | — | — |
| 1 p.m. | 92% | 68% | 84% | — |
| 2 p.m. | 75% | 61% | — | — |
| 3 p.m. | — | 49% | — | — |
| 4 p.m. | 72% | 52% | — | — |
| 5 p.m. | 71% | 64% | 76% | — |
| 6 p.m. | 79% | — | 61% | — |
| 8 p.m. | — | — | 76% | — |
| 9 p.m. | — | — | 82% | 84% |
Last flight of the day
On SLC → DEN, each airline's last flight of the day was cancelled 1.0% of the time, against 0.4% for its earlier flights (2.7× as often). It arrived 3+ hours late 1.3% of the time (earlier flights: 1.1%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.
| Airline | Last departure | Last: cancelled | Last: 3h+ late | Earlier: cancelled | Next morning |
|---|---|---|---|---|---|
| Delta Air Lines | 9:05 p.m. | 0.0% | 0.5% | 0.2% | first flight 7:45 a.m. |
| Frontier Airlines | 7:08 p.m. | 1.1% | 2.2% | 0.8% | first flight 6:05 a.m. |
| United Airlines | 5:57 p.m. | 1.9% | 1.6% | 0.3% | first flight 5:15 a.m. |
| Southwest Airlines | 9:40 p.m. | 1.1% | 0.8% | 0.5% | first flight 6:00 a.m. |
Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.
If you need to be in DEN tonight, book an earlier flight so there's a backup if it's cancelled.
By month
Each calendar month pooled over 2023–2026. Best: November (83%). Worst: August (70%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 1,168 | 78% | 0.3% |
| Tuesday | 1,081 | 81% | 0.6% |
| Wednesday | 1,100 | 78% | 0.4% |
| Thursday | 1,137 | 78% | 0.3% |
| Friday | 1,150 | 74% | 0.8% |
| Saturday | 949 | 82% | 0.9% |
| Sunday | 1,124 | 79% | 0.4% |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: air traffic/airport 15 · airline 12 · weather 12
Month by month
Flight numbers on this route
Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.
| Flight | Departs | Flights | On time | Cancelled | Typical arrival | Operated by |
|---|---|---|---|---|---|---|
| UA 5683 | 5:15 a.m. | 264 | 94% | 0.0% | −19 min | SkyWest |
| F9 3220 | 6:05 a.m. | 158 | 85% | 1.3% | −17 min | Frontier Airlines |
| UA 1232 | 7:00 a.m. | 198 | 94% | 0.5% | −12 min | United Airlines |
| F9 3862 | 8:16 a.m. | 360 | 79% | 0.3% | −10 min | Frontier Airlines |
| UA 5642 | 8:30 a.m. | 255 | 83% | 0.0% | −5 min | SkyWest |
| DL 1553 | 10:15 a.m. | 324 | 78% | 0.3% | −8 min | Delta Air Lines |
| F9 3982 | 11:49 a.m. | 247 | 74% | 0.8% | −7 min | Frontier Airlines |
| UA 4720 | 1:05 p.m. | 283 | 90% | 0.4% | −14 min | SkyWest |
| DL 1623 | 1:20 p.m. | 359 | 84% | 0.6% | −7 min | Delta Air Lines |
| UA 1662 | 2:33 p.m. | 238 | 76% | 0.4% | −10 min | United Airlines |
| DL 1586 | 6:30 p.m. | 344 | 68% | 0.0% | −4 min | Delta Air Lines |
| DL 1667 | 8:59 p.m. | 272 | 79% | 0.0% | −8 min | Delta Air Lines |
| F9 4252 | 10:50 p.m. | 147 | 79% | 1.4% | −17 min | Frontier Airlines |
Worst days in the past year
| Date | Flights | On time | Cancelled |
|---|---|---|---|
| Feb 17, 2026 | 22 | 14% | 2 |
| Mar 6, 2026 | 22 | 18% | 1 |
| Dec 19, 2025 | 21 | 19% | 2 |
| Aug 13, 2026 | 22 | 36% | 0 |
| Sep 11, 2025 | 23 | 39% | 0 |
Questions
How often are flights from SLC to DEN on time?
78% of 7,709 scheduled flights from Salt Lake City, UT to Denver, CO arrived within 15 minutes of schedule between September 2025 and August 2026. 0.5% were cancelled.
What is the best time of day to fly SLC to DEN?
Flights scheduled to leave at 5 a.m. were the most reliable (95% on time). The 3 p.m. departures were the least (58%).
Which airline is most on time from SLC to DEN?
United Airlines: 83% of its 2,696 flights on the route arrived on time. Southwest Airlines: 72%. Delta Air Lines: 79%. Frontier Airlines: 79%.
What month has the most delays from SLC to DEN?
August (70% on time). The best month is November (83%), over 2023–2026.
Is the last flight of the day from SLC to DEN more likely to be cancelled?
Yes. Each airline's last SLC–DEN flight of the day was cancelled 1.0% of the time over the past year, against 0.4% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- DEN → SLC (return)
- Salt Lake City (SLC) delays by hour
- Flights into Denver (DEN)
- United Airlines on-time record
- Southwest Airlines on-time record
- Delta Air Lines on-time record
- Frontier Airlines on-time record
- Connecting off this flight? Check the risk
Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.