66% of flights from Portland to San Francisco arrived on time over the past 12 months. That is worse than the typical U.S. route. The 5 a.m. departures ran on time 94% of the time; the 11 a.m. ones 43%. Most reliable airline: Alaska Airlines (66%). 10% 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 PDX → SFO: when a flight was late, it was under 45 minutes late 58% of the time. About 1 in 11 flights landed an hour or more late, and 1 in 72 three hours or more; 0.5% were cancelled outright.
- On time or early66%
- 15–30 min late12%
- 30–60 min late13%
- 1–2 hours late5.8%
- 2–3 hours late1.7%
- 3+ hours late1.4%
- Diverted0.1%
- Cancelled0.5%
Share of all 3,733 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 | 2,032 | 66% | 0.3% | 0 min | 9.9% | +60 min | United Airlines 85%, SkyWest 15% |
| Alaska Airlines | 1,701 | 66% | 0.7% | +2 min | 7.8% | +53 min | Alaska Airlines 82%, Horizon Air 14%, SkyWest 4% |
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 PDX). Delays build through the day as late planes knock on, so early flights usually do best.
By airline and hour
| Departs | United Airlines | Alaska Airlines |
|---|---|---|
| 5 a.m. | 94% | — |
| 7 a.m. | 50% | 59% |
| 10 a.m. | — | 70% |
| 11 a.m. | 43% | — |
| 1 p.m. | 68% | — |
| 2 p.m. | — | 73% |
| 3 p.m. | 76% | — |
| 5 p.m. | 78% | 65% |
| 7 p.m. | 53% | — |
| 9 p.m. | — | 56% |
Last flight of the day
On PDX → SFO, each airline's last flight of the day was cancelled 0.5% of the time, against 0.4% for its earlier flights (1.3× as often). It arrived 3+ hours late 1.0% of the time (earlier flights: 1.5%). 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 |
|---|---|---|---|---|---|
| Alaska Airlines | 9:45 p.m. | 0.8% | 0.3% | 0.6% | first flight 7:19 a.m. |
| United Airlines | 6:03 p.m. | 0.3% | 1.6% | 0.3% | first flight 5:15 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 SFO tonight, book an earlier flight so there's a backup if it's cancelled.
By month
Each calendar month pooled over 2023–2026. Best: October (83%). Worst: April (59%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 577 | 63% | 0.2% |
| Tuesday | 511 | 73% | 0.4% |
| Wednesday | 513 | 65% | 0.2% |
| Thursday | 554 | 59% | 0.7% |
| Friday | 548 | 63% | 0.9% |
| Saturday | 473 | 76% | 0.6% |
| Sunday | 557 | 65% | 0.2% |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: air traffic/airport 10 · airline 6 · weather 1
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 |
|---|---|---|---|---|---|---|
| AS 526 | 7:00 a.m. | 305 | 57% | 0.0% | +9 min | Alaska Airlines |
| AS 2112 | 2:30 p.m. | 208 | 60% | 1.4% | +6 min | Horizon Air |
| AS 236 | 2:49 p.m. | 228 | 71% | 0.4% | +3 min | Alaska Airlines |
| AS 1393 | 5:50 p.m. | 230 | 65% | 0.4% | 0 min | Alaska Airlines |
Worst days in the past year
| Date | Flights | On time | Cancelled |
|---|---|---|---|
| Feb 15, 2026 | 9 | 0% | 0 |
| Dec 21, 2025 | 8 | 0% | 0 |
| Jan 5, 2026 | 8 | 0% | 0 |
| Dec 26, 2025 | 8 | 0% | 2 |
| Apr 20, 2026 | 12 | 8% | 1 |
Nearby airport alternatives
Other ways to make the same trip, using airports within 60 miles of Portland or San Francisco. PDX → SJC has been 17 points more reliable.
| Route | Flights | On time | Cancelled |
|---|---|---|---|
| PDX → SFO (this route) | 3,733 | 66% | 0.5% |
| PDX → SJC Portland to San Jose | 2,554 | 83% | 0.6% |
| PDX → OAK Portland to Oakland | 1,914 | 80% | 0.7% |
Questions
How often are flights from PDX to SFO on time?
66% of 3,733 scheduled flights from Portland, OR to San Francisco, CA 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 PDX to SFO?
Flights scheduled to leave at 5 a.m. were the most reliable (94% on time). The 11 a.m. departures were the least (43%).
Which airline is most on time from PDX to SFO?
Alaska Airlines: 66% of its 1,701 flights on the route arrived on time. United Airlines: 66%.
What month has the most delays from PDX to SFO?
April (59% on time). The best month is October (83%), over 2023–2026.
Is the last flight of the day from PDX to SFO more likely to be cancelled?
Yes. Each airline's last PDX–SFO flight of the day was cancelled 0.5% 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
- SFO → PDX (return)
- Portland (PDX) delays by hour
- Flights into San Francisco (SFO)
- United Airlines on-time record
- Alaska 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.