79% of flights from San Diego to Boise arrived on time over the past 12 months. That is about the typical U.S. route. The 10 a.m. departures ran on time 80% of the time; the 5 p.m. ones 73%. Most reliable airline: Alaska Airlines (82%). 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 SAN → BOI: when a flight was late, it was under 45 minutes late 56% of the time. About 1 in 16 flights landed an hour or more late, and 1 in 231 three hours or more; 0.3% were cancelled outright.
- On time or early79%
- 15–30 min late7.2%
- 30–60 min late7.5%
- 1–2 hours late4.9%
- 2–3 hours late1.0%
- 3+ hours late0.4%
- Diverted0.0%
- Cancelled0.3%
Share of all 1,153 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 |
|---|---|---|---|---|---|---|---|
| Alaska Airlines | 727 | 82% | 0.5% | −9 min | 5.1% | +56 min | SkyWest 49%, Alaska Airlines 35%, Horizon Air 16% |
| Southwest Airlines | 426 | 73% | 0.0% | −0 min | 8.5% | +55 min | Southwest 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 SAN). Delays build through the day as late planes knock on, so early flights usually do best.
By airline and hour
| Departs | Alaska Airlines |
|---|---|
| 10 a.m. | 80% |
| 8 p.m. | 79% |
Last flight of the day
On SAN → BOI, each airline's last flight of the day was cancelled 0.6% of the time, against 0.2% for its earlier flights (3.0× as often). It arrived 3+ hours late 0.4% of the time (earlier flights: 0.4%). 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 | 5:06 p.m. | 0.8% | 0.3% | 0.3% | first flight 10:30 a.m. |
| Southwest Airlines | 6:30 p.m. | 0.0% | 0.9% | 0.0% | first flight 8:45 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 BOI tonight, book an earlier flight so there's a backup if it's cancelled.
By month
Each calendar month pooled over 2023–2026. Best: April (83%). Worst: January (70%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 182 | 77% | 0.0% |
| Tuesday | 152 | 87% | 0.0% |
| Wednesday | 151 | 83% | 0.7% |
| Thursday | 176 | 67% | 1.7% |
| Friday | 177 | 73% | 0.0% |
| Saturday | 148 | 87% | 0.0% |
| Sunday | 167 | 78% | 0.0% |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: weather 3 · airline 1
Month by month
Worst days in the past year
| Date | Flights | On time | Cancelled |
|---|---|---|---|
| May 21, 2026 | 4 | 0% | 0 |
| Dec 31, 2025 | 3 | 0% | 0 |
| Nov 21, 2025 | 3 | 0% | 0 |
| Dec 19, 2025 | 3 | 0% | 0 |
| Jun 18, 2026 | 4 | 25% | 0 |
Questions
How often are flights from SAN to BOI on time?
79% of 1,153 scheduled flights from San Diego, CA to Boise, ID arrived within 15 minutes of schedule between September 2025 and August 2026. 0.4% were cancelled.
What is the best time of day to fly SAN to BOI?
Flights scheduled to leave at 10 a.m. were the most reliable (80% on time). The 5 p.m. departures were the least (73%).
Which airline is most on time from SAN to BOI?
Alaska Airlines: 82% of its 727 flights on the route arrived on time. Southwest Airlines: 73%.
What month has the most delays from SAN to BOI?
January (70% on time). The best month is April (83%), over 2023–2026.
Is the last flight of the day from SAN to BOI more likely to be cancelled?
Yes. Each airline's last SAN–BOI flight of the day was cancelled 0.6% of the time over the past year, against 0.2% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- BOI → SAN (return)
- San Diego (SAN) delays by hour
- Flights into Boise /Gowen (BOI)
- Alaska Airlines on-time record
- Southwest 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.