Flight number record
OO 3881
SkyWest Airlines · Seattle to Sacramento
- Route
- SEA → SMF
- Departs
- 08:25
- Flights
- 359
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 3881, 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 3881 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 14 points better than the national rate of 77.3%. When something does go wrong the average delay runs a little over an hour. That rests on 359 flights, with a median arrival 11 minutes early.
Set against the rest of the country, OO 3881's record is 14 points better than the US average of 77.3%. That gap is worth roughly 140 fewer late arrivals for every thousand flights.
Key figures
On time
91.3%
Arrivals under 15 minutes late, of 357 completed flights
Avg delay
78 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
1 hour+ late
3.6%
National rate is 8.3%
These figures cover 359 flights between September 2025 and August 2026. The median arrival is 11 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 3881 flies
OO 3881 flies SEA to SMF without a single fixed slot. Its most common scheduled departure was 08:25, used on 89 of 359 flights, with 08:20 (70 flights) next.
- Departs 08:2589 flights24.8%
- Departs 08:2070 flights19.5%
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 08:25 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and OO 3881 runs 7 points better at 91.3%. 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 3881 next to SEA to SMF
Every carrier on SEA to SMF combined arrived on time 82.1% of the time across 4,387 flights, so OO 3881 is 9 points ahead of it. SkyWest flew 1,839 flights on the same city pair under all its flight numbers, including this one, and those ran 89.1% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 13 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 3881thin sample | 359 | 91.3% | 78 min | 0.00% | A+ |
| All SkyWest Airlines on SEA–SMF | 1,839 | 89.1% | 63 min | 0.27% | A+ |
| All carriers on SEA–SMF | 4,387 | 82.1% | 51 min | 0.39% | B+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 3881 quarter by quarter
OO 3881 did not run the same all year. Its best quarter was Apr–Jun 2026 at 97.8% on time and its weakest Jul–Sep 2025 at 86.7%, a swing of 11 points on roughly 72 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 flights86.7%
- Oct–Dec 202586 flights89.5%
- Jan–Mar 202690 flights87.5%
- Apr–Jun 202691 flights97.8%
- Jul–Sep 202662 flights91.9%
Scale runs 80% to 100%.
By weekday, OO 3881 ranged from 85.7% on Friday to 96.2% on Tuesday. With about 51 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 3881 runs when it is late
OO 3881 often beats the schedule: 141 of 357 completed flights, 39%, arrived 15 minutes or more early. The 31 late arrivals split 14 under half an hour, 4 between 30 and 60 minutes, and 13 an hour or more.
- 15+ min early141 flights39.5%
- Within 15 min185 flights51.8%
- 15–29 min late14 flights3.9%
- 30–59 min late4 flights1.1%
- 1–2 hours late7 flights2.0%
- 2+ hours late6 flights1.7%
Scale runs 0% to 100%.
Share of 357 completed flights by arrival against schedule.
3 of 25 late departures made up the time and arrived on time, 12% of them. 9 flights left on time and still arrived late.
The worst days
Worst days for OO 3881
The latest arrival of the period was on 13 February 2026, 7 hours 5 minutes behind schedule; most of its delay minutes were filed as extreme weather. Three of the five worst days fell in March 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 February 2026 | 7 hours 5 minutes | Extreme weather |
| 31 December 2025 | 5 hours 23 minutes | Carrier |
| 30 March 2026 | 3 hours 15 minutes | Extreme weather |
| 13 March 2026 | 2 hours 15 minutes | Carrier |
| 25 March 2026 | 2 hours 9 minutes | Carrier |
Delay causes
Why OO 3881 runs late
Carrier accounts for 66% of the 2,414 delay minutes carriers reported here, and the remaining four split what is left.
- 66%Carrier
- 30%Extreme weather
- 4%National Airspace System
Extreme weather accounts for 30% 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 5.1 times the usual weather exposure. The split is drawn from 2,414 delay minutes reported on OO 3881.
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 3.6% 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 605 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The same number turns up on one other city pair in the data, including SMF to SEA (207), but none flew often enough under OO 3881 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SEA to SMF only.
One caution: this is a thin sample. 359 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 3881
For a booking, OO 3881 has one of the better records a US domestic flight can show: 91.3% on time and 0.00% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- SEA to SMF, every carrier and departure
- SMF to SEA, the return direction
- SkyWest Airlines 4125 on the same route90.5%
- SkyWest Airlines 4131 on the same route88.4%
- SkyWest Airlines 4043 on the same route88.9%
- Alaska Airlines 681 on the same route81.9%
- Seattle-Tacoma International (SEA) delay statistics
- Sacramento International (SMF) 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.