Flight number record
OO 3678
SkyWest Airlines · Boise to Seattle
- Route
- BOI → SEA
- Departs
- 07:30
- Flights
- 334
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 3678, check with SkyWest Airlines. SkyWest Airlines flies under contract for larger airlines, so a ticket for this flight may show a different airline code and number.
OO 3678 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 13 points better than the national rate of 77.3%. When something does go wrong the average delay runs about 50 minutes. That rests on 334 flights, with a median arrival 17 minutes early.
Set against the rest of the country, OO 3678's record is 13 points better than the US average of 77.3%. That gap is worth roughly 131 fewer late arrivals for every thousand flights.
Key figures
On time
90.4%
Arrivals under 15 minutes late, of 332 completed flights
Avg delay
50 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
1 hour+ late
3.0%
National rate is 8.3%
These figures cover 334 flights between September 2025 and August 2026. The median arrival is 17 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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Schedule
When OO 3678 flies
OO 3678 flies BOI to SEA without a single fixed slot. Its most common scheduled departure was 07:30, used on 152 of 334 flights, with 07:25 (38 flights) and 07:40 (34 flights) next.
- Departs 07:30152 flights45.5%
- Departs 07:2538 flights11.4%
- Departs 07:4034 flights10.2%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 07:30 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and OO 3678 runs level with that at 90.4%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
OO 3678 next to BOI to SEA
Every carrier on BOI to SEA combined arrived on time 84.9% of the time across 3,730 flights, so OO 3678 is 6 points ahead of it. SkyWest flew 2,754 flights on the same city pair under all its flight numbers, including this one, and those ran 85.9% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 12 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 3678thin sample | 334 | 90.4% | 50 min | 0.00% | A+ |
| All SkyWest Airlines on BOI–SEA | 2,754 | 85.9% | 61 min | 0.29% | A+ |
| All carriers on BOI–SEA | 3,730 | 84.9% | 56 min | 0.40% | B+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 3678 quarter by quarter
OO 3678 did not run the same all year. Its best quarter was Jul–Sep 2025 at 100.0% on time and its weakest Jul–Sep 2026 at 83.9%, a swing of 16 points on roughly 67 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights100.0%
- Oct–Dec 202592 flights92.3%
- Jan–Mar 202690 flights89.9%
- Apr–Jun 202660 flights90.0%
- Jul–Sep 202662 flights83.9%
Scale runs 75% to 100%.
By weekday, OO 3678 ranged from 84.8% on Thursday to 95.7% on Wednesday. With about 48 flights behind each day, a spread of 11 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late OO 3678 runs when it is late
OO 3678 often beats the schedule: 190 of 332 completed flights, 57%, arrived 15 minutes or more early. The 32 late arrivals split 14 under half an hour, 8 between 30 and 60 minutes, and 10 an hour or more.
- 15+ min early190 flights57.2%
- Within 15 min110 flights33.1%
- 15–29 min late14 flights4.2%
- 30–59 min late8 flights2.4%
- 1–2 hours late8 flights2.4%
- 2+ hours late2 flights0.6%
Scale runs 0% to 100%.
Share of 332 completed flights by arrival against schedule.
4 of 23 late departures made up the time and arrived on time, 17% of them. 13 flights left on time and still arrived late.
The worst days
Worst days for OO 3678
The latest arrival of the period was on 16 July 2026, 3 hours 7 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. On three of the five worst days the largest share was filed as extreme weather.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 16 July 2026 | 3 hours 7 minutes | National Airspace System |
| 8 January 2026 | 2 hours 6 minutes | Extreme weather |
| 30 March 2026 | 1 hour 57 minutes | Extreme weather |
| 21 March 2026 | 1 hour 37 minutes | Carrier |
| 14 August 2026 | 1 hour 34 minutes | Extreme weather |
Delay causes
Why OO 3678 runs late
Carrier accounts for 49% of the 1,608 delay minutes carriers reported here, and the remaining four split what is left.
- 49%Carrier
- 27%National Airspace System
- 24%Extreme weather
Extreme weather accounts for 24% 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 quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 3.9 times the usual weather exposure. The split is drawn from 1,608 delay minutes reported on OO 3678.
Cancellations are rare at 0.00%, below the national 1.89% and low enough to earn the plus on the grade. Almost no flights are called off; the risk here is arriving late, not not arriving.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 3.0% 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.
The same number turns up on four other city pairs in the data, including SEA to BOI (86), CLE to DTW (25) and DTW to CLE (25), but none flew often enough under OO 3678 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to BOI to SEA only.
One caution: this is a thin sample. 334 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.
What to do with this
Booking OO 3678
For a booking, OO 3678 has one of the better records a US domestic flight can show: 90.4% on time and 0.00% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- BOI to SEA, every carrier and departure
- SEA to BOI, the return direction
- SkyWest Airlines 3775 on the same route95.0%
- SkyWest Airlines 3740 on the same route82.1%
- SkyWest Airlines 4127 on the same route82.8%
- Seattle-Tacoma International (SEA) delay statistics
- SkyWest Airlines on-time record
- Every SkyWest Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Worst months to fly in the US, ranked by the data
A flight number here means SkyWest Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
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.