Flight number record
OO 5978
SkyWest Airlines · Denver to Fresno
- Route
- DEN → FAT
- Departs
- 15:45
- Flights
- 317
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 5978, 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 5978 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 10 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 317 flights, with a median arrival 10 minutes early.
Set against the rest of the country, OO 5978's record is 10 points better than the US average of 77.3%. That gap is worth roughly 98 fewer late arrivals for every thousand flights.
Key figures
On time
87.1%
Arrivals under 15 minutes late, of 317 completed flights
Avg delay
76 min
Across delayed arrivals only, not all flights
Cancelled
0.00%
National rate is 1.89%
1 hour+ late
4.7%
National rate is 8.3%
These figures cover 317 flights between September 2025 and August 2026. The median arrival is 10 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 5978 flies
OO 5978 flies DEN to FAT without a single fixed slot. Its most common scheduled departure was 15:45, used on 79 of 317 flights, with 15:50 (53 flights) and 15:40 (52 flights) next.
- Departs 15:4579 flights24.9%
- Departs 15:5053 flights16.7%
- Departs 15:4052 flights16.4%
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 15:45 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 71.9%, and OO 5978 runs 15 points better at 87.1%. 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 5978 next to DEN to FAT
Every carrier on DEN to FAT combined arrived on time 80.3% of the time across 1,452 flights, so OO 5978 is 7 points ahead of it. SkyWest flew 748 flights on the same city pair under all its flight numbers, including this one, and those ran 87.8% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight beats by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 5978thin sample | 317 | 87.1% | 76 min | 0.00% | A+ |
| All SkyWest Airlines on DEN–FAT | 748 | 87.8% | 63 min | 0.00% | A+ |
| All carriers on DEN–FAT | 1,452 | 80.3% | 54 min | 0.14% | B+ |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 5978 quarter by quarter
Quarter by quarter OO 5978 held fairly steady: 90.0% in Jul–Sep 2025, 89.0% in Oct–Dec 2025, 90.0% in Jan–Mar 2026 and 83.5% in Apr–Jun 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202530 flights90.0%
- Oct–Dec 202591 flights89.0%
- Jan–Mar 202690 flights90.0%
- Apr–Jun 202685 flights83.5%
- Jul–Sep 202621 flights—
Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, OO 5978 ranged from 82.6% on Monday to 93.2% on Thursday. With about 45 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 5978 runs when it is late
OO 5978 often beats the schedule: 128 of 317 completed flights, 40%, arrived 15 minutes or more early. The 41 late arrivals split 8 under half an hour, 18 between 30 and 60 minutes, and 15 an hour or more.
- 15+ min early128 flights40.4%
- Within 15 min148 flights46.7%
- 15–29 min late8 flights2.5%
- 30–59 min late18 flights5.7%
- 1–2 hours late8 flights2.5%
- 2+ hours late7 flights2.2%
Scale runs 0% to 100%.
Share of 317 completed flights by arrival against schedule.
8 of 42 late departures made up the time and arrived on time, 19% of them. 7 flights left on time and still arrived late.
The worst days
Worst days for OO 5978
The latest arrival of the period was on 6 March 2026, 7 hours 2 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across March, August, December, November and February, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 6 March 2026 | 7 hours 2 minutes | Carrier |
| 15 August 2026 | 5 hours 5 minutes | Late-arriving aircraft |
| 19 December 2025 | 3 hours 36 minutes | National Airspace System |
| 29 November 2025 | 2 hours 53 minutes | Late-arriving aircraft |
| 17 February 2026 | 2 hours 28 minutes | National Airspace System |
Delay causes
Why OO 5978 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 3,125 reported delay minutes.
- 37%Late-arriving aircraft
- 35%Carrier
- 26%National Airspace System
- 2%Extreme weather
37% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 3,125 reported delay minutes here, that single category outweighs weather by 25 to one. The split is drawn from 3,125 delay minutes reported on OO 5978.
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 4.7% 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 844 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 317 flights under OO 5978 in the data flew DEN to FAT. 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. 317 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 5978
For a booking, OO 5978 has one of the better records a US domestic flight can show: 87.1% on time and 0.00% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- DEN to FAT, every carrier and departure
- FAT to DEN, the return direction
- 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
- Why the first flight of the morning is statistically safest
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.