Flight number record
OO 5966
SkyWest Airlines · Arcata/Eureka to Denver
- Route
- ACV → DEN
- Departs
- 12:30
- Flights
- 364
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 5966, 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 5966 sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.3%. The late ones land an hour and a half behind schedule. That rests on 364 flights, with a median arrival 5 minutes early.
Key figures
On time
75.8%
Arrivals under 15 minutes late, of 355 completed flights
Avg delay
98 min
Across delayed arrivals only, not all flights
Cancelled
1.10%
National rate is 1.89%
1 hour+ late
12.1%
National rate is 8.3%
These figures cover 364 flights between September 2025 and August 2026. Beyond the headline rate, 12.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When OO 5966 flies
OO 5966 flies ACV to DEN without a single fixed slot. Its most common scheduled departure was 12:30, used on 195 of 364 flights, with 12:34 (104 flights) next.
- Departs 12:30195 flights53.6%
- Departs 12:34104 flights28.6%
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 12:30 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and OO 5966 runs 3 points worse at 75.8%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
OO 5966 next to ACV to DEN
Across its whole network SkyWest Airlines managed 78.7%, which this flight trails by 3 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 5966thin sample | 364 | 75.8% | 98 min | 1.10% | B |
| All SkyWest Airlines on ACV–DENthin sample | 364 | 75.8% | 98 min | 1.10% | B |
| All carriers on ACV–DENthin sample | 364 | 75.8% | 98 min | 1.10% | B |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 5966 quarter by quarter
OO 5966 did not run the same all year. Its best quarter was Oct–Dec 2025 at 90.1% on time and its weakest Jul–Sep 2026 at 61.0%, a swing of 29 points on roughly 73 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 flights80.0%
- Oct–Dec 202591 flights90.1%
- Jan–Mar 202690 flights82.0%
- Apr–Jun 202691 flights62.8%
- Jul–Sep 202662 flights61.0%
Scale runs 55% to 95%.
By weekday, OO 5966 did best on Thursday at 82.4% on time and worst on Wednesday at 68.0%. Each day rests on about 52 flights, so a gap of 14 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 5966 runs when it is late
OO 5966 often beats the schedule: 109 of 355 completed flights, 31%, arrived 15 minutes or more early. The 86 late arrivals split 25 under half an hour, 18 between 30 and 60 minutes, and 43 an hour or more.
- 15+ min early109 flights30.7%
- Within 15 min160 flights45.1%
- 15–29 min late25 flights7.0%
- 30–59 min late18 flights5.1%
- 1–2 hours late23 flights6.5%
- 2+ hours late20 flights5.6%
Scale runs 0% to 100%.
Share of 355 completed flights by arrival against schedule.
11 of 80 late departures made up the time and arrived on time, 14% of them. 17 flights left on time and still arrived late.
The worst days
Worst days for OO 5966
The latest arrival of the period was on 18 October 2025, 20 hours behind schedule; most of its delay minutes were filed as extreme weather. The five worst days are spread across October, April, February, July and June, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 18 October 2025 | 20 hours | Extreme weather |
| 20 April 2026 | 4 hours 52 minutes | National Airspace System |
| 18 February 2026 | 4 hours 37 minutes | Late-arriving aircraft |
| 5 July 2026 | 4 hours 33 minutes | Late-arriving aircraft |
| 22 June 2026 | 4 hours 13 minutes | National Airspace System |
Delay causes
Why OO 5966 runs late
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 8,452 reported delay minutes.
- 38%Extreme weather
- 30%National Airspace System
- 24%Late-arriving aircraft
- 7%Carrier
Extreme weather accounts for 38% 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 6.4 times the usual weather exposure. The split is drawn from 8,452 delay minutes reported on OO 5966.
Cancellations sit at 1.10% against a national 1.89%, which is ordinary. Diversions add another 1.37%.
Connections and routes
What a delay on this flight costs
12.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The 1,026 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.
Every one of the 364 flights under OO 5966 in the data flew ACV to DEN. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 364 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 5966
For a booking, OO 5966 is a flight to put a long connection behind. 12.1% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.
Related
Where to go next
- Denver International (DEN) 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
- How often a connection fails at the major US hubs
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.