Flight number record
OO 3953
SkyWest Airlines · Portland to Seattle
- Route
- PDX → SEA
- Departs
- 09:20
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 3953, 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 3953 lands a B+, 5 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about 45 minutes on average. That rests on 365 flights, with a median arrival 8 minutes early.
Set against the rest of the country, OO 3953's record is 5 points better than the US average of 77.3%. That gap is worth roughly 53 fewer late arrivals for every thousand flights.
Key figures
On time
82.6%
Arrivals under 15 minutes late, of 363 completed flights
Avg delay
45 min
Across delayed arrivals only, not all flights
Cancelled
0.55%
National rate is 1.89%
1 hour+ late
3.9%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 8 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 3953 flies
OO 3953 flies PDX to SEA without a single fixed slot. Its most common scheduled departure was 09:20, used on 93 of 365 flights, with 09:17 (63 flights) next.
- Departs 09:2093 flights25.5%
- Departs 09:1763 flights17.3%
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 09:20 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and OO 3953 runs level with that at 82.6%. 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 3953 next to PDX to SEA
Every carrier on PDX to SEA combined arrived on time 84.9% of the time across 4,927 flights, so OO 3953 is 2 points behind it. SkyWest flew 3,472 flights on the same city pair under all its flight numbers, including this one, and those ran 85.5% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 4 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 3953 | 365 | 82.6% | 45 min | 0.55% | B+ |
| All SkyWest Airlines on PDX–SEA | 3,472 | 85.5% | 59 min | 0.58% | A+ |
| All carriers on PDX–SEA | 4,927 | 84.9% | 54 min | 0.71% | B+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 3953 quarter by quarter
Quarter by quarter OO 3953 held fairly steady: 86.7% in Jul–Sep 2025, 80.2% in Oct–Dec 2025, 87.6% in Jan–Mar 2026, 78.0% in Apr–Jun 2026 and 83.9% in Jul–Sep 2026. A spread of 10 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202530 flights86.7%
- Oct–Dec 202592 flights80.2%
- Jan–Mar 202690 flights87.6%
- Apr–Jun 202691 flights78.0%
- Jul–Sep 202662 flights83.9%
Scale runs 70% to 95%.
By weekday, OO 3953 ranged from 76.9% on Thursday to 86.5% on Tuesday. With about 52 flights behind each day, a spread of 10 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late OO 3953 runs when it is late
OO 3953 often beats the schedule: 134 of 363 completed flights, 37%, arrived 15 minutes or more early. Most of the lateness is short. 32 of the 63 late arrivals were under half an hour behind, and 14 reached an hour or more.
- 15+ min early134 flights36.9%
- Within 15 min166 flights45.7%
- 15–29 min late32 flights8.8%
- 30–59 min late17 flights4.7%
- 1–2 hours late11 flights3.0%
- 2+ hours late3 flights0.8%
Scale runs 0% to 100%.
Share of 363 completed flights by arrival against schedule.
8 of 38 late departures made up the time and arrived on time, 21% of them. In the other direction, 33 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at SEA.
The worst days
Worst days for OO 3953
The latest arrival of the period was on 28 March 2026, 4 hours 46 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 28 March 2026 | 4 hours 46 minutes | Carrier |
| 16 July 2026 | 4 hours 34 minutes | Carrier |
| 14 June 2026 | 2 hours 6 minutes | Extreme weather |
| 1 November 2025 | 1 hour 28 minutes | Carrier |
| 31 December 2025 | 1 hour 23 minutes | Extreme weather |
Delay causes
Why OO 3953 runs late
Carrier accounts for 64% of the 2,854 delay minutes carriers reported here, and the remaining four split what is left.
- 64%Carrier
- 21%National Airspace System
- 15%Extreme weather
Extreme weather accounts for 15% 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 2.4 times the usual weather exposure. The split is drawn from 2,854 delay minutes reported on OO 3953.
Cancellations are rare at 0.55%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is 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 3.9% 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.
OO 3953 is not only a PDX to SEA flight. It also flew SEA to PDX (365 flights, 93.1% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.
One caution: this is a thin sample. 365 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.
| Also flown as | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SEA to PDX | 365 | 93.1% | 63 min | 0.27% | A+ |
What to do with this
Booking OO 3953
For a booking, read OO 3953 as 82.6% on time with 0.55% cancelled over 365 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- PDX to SEA, every carrier and departure
- SEA to PDX, the return direction
- SkyWest Airlines 3802 on the same route84.7%
- SkyWest Airlines 3918 on the same route84.2%
- SkyWest Airlines 3818 on the same route90.9%
- Alaska Airlines 499 on the same route92.7%
- Portland International (PDX) delay statistics
- 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.