63% of flights from San Francisco to Aspen arrived on time over the past 12 months. That is worse than the typical U.S. route. 21% 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 SFO → ASE: when a flight was late, it was under 45 minutes late 43% of the time. About 1 in 8 flights landed an hour or more late, and 1 in 24 three hours or more; 2.4% were cancelled outright.
- On time or early63%
- 15–30 min late6.6%
- 30–60 min late9.8%
- 1–2 hours late6.1%
- 2–3 hours late2.9%
- 3+ hours late4.3%
- Diverted5.3%
- Cancelled2.4%
Share of all 376 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 | 376 | 63% | 2.4% | −1 min | 13.3% | +133 min | SkyWest |
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 SFO). Delays build through the day as late planes knock on, so early flights usually do best.
Last flight of the day
On SFO → ASE, each airline's last flight of the day was cancelled 4.2% of the time, against 2.9% for its earlier flights (1.5× as often). It arrived 3+ hours late 3.4% of the time (earlier flights: 5.1%). 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 |
|---|---|---|---|---|---|
| United Airlines | 4:25 p.m. | 4.2% | 3.4% | 2.9% | first flight 4:25 p.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 ASE tonight, book an earlier flight so there's a backup if it's cancelled.
By month
Each calendar month pooled over 2023–2026. Best: January (68%). Worst: February (56%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 52 | — | — |
| Tuesday | 46 | — | — |
| Wednesday | 51 | — | — |
| Thursday | 54 | — | — |
| Friday | 54 | — | — |
| Saturday | 61 | — | — |
| Sunday | 58 | — | — |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: weather 7 · airline 1 · air traffic/airport 1
Month by month
Not enough months with data to draw a trend.
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 5711 | 4:25 p.m. | 144 | 51% | 0.7% | +8 min | SkyWest |
Worst days in the past year
| Date | Flights | On time | Cancelled |
|---|---|---|---|
| Feb 16, 2026 | 3 | 0% | 1 |
| Feb 13, 2026 | 3 | 0% | 0 |
| Feb 18, 2026 | 3 | 0% | 1 |
| Feb 19, 2026 | 3 | 0% | 0 |
| Feb 14, 2026 | 3 | 0% | 0 |
Questions
How often are flights from SFO to ASE on time?
63% of 376 scheduled flights from San Francisco, CA to Aspen, CO arrived within 15 minutes of schedule between September 2025 and August 2026. 2.4% were cancelled.
What month has the most delays from SFO to ASE?
February (56% on time). The best month is January (68%), over 2023–2026.
Is the last flight of the day from SFO to ASE more likely to be cancelled?
Yes. Each airline's last SFO–ASE flight of the day was cancelled 4.2% of the time over the past year, against 2.9% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- ASE → SFO (return)
- San Francisco (SFO) delays by hour
- Flights into Aspen-Pitkin (Sardy ) (ASE)
- United 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.