Flight number record

OO 5978

SkyWest Airlines · Denver to Fresno

Route: DEN → FAT
Departs: 15:45
Flights: 358
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 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+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 358 flights, with a median arrival 10 minutes early.

Set against the rest of the country, OO 5978's record is 8 points better than the US average of 77.6%. That gap is worth roughly 82 fewer late arrivals for every thousand flights.

On time

85.8%

Arrivals under 15 minutes late, of 358 completed flights

Avg delay

74 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

1 hour+ late

4.7%

National rate is 8.1%

These figures cover 358 flights between July 2025 and June 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.

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 92 of 358 flights, with 15:42 (70 flights) and 15:50 (53 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 15:4592 flights25.7%
Departs 15:4270 flights19.6%
Departs 15:5053 flights14.8%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

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 72.4%, and OO 5978 runs 13 points better at 85.8%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

OO 5978 next to DEN to FAT

Every carrier on DEN to FAT combined arrived on time 81.0% of the time across 1,453 flights, so OO 5978 is 5 points ahead of it. SkyWest flew 749 flights on the same city pair under all its flight numbers, including this one, and those ran 87.3% on time. Across its whole network SkyWest Airlines managed 79.0%, which this flight beats by 7 points.

OO 5978 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 5978thin sample	358	85.8%	74 min	0.00%	A+
All SkyWest Airlines on DEN–FAT	749	87.3%	65 min	0.00%	A+
All carriers on DEN–FAT	1,453	81.0%	55 min	0.14%	B+
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 5978 quarter by quarter

Quarter by quarter OO 5978 held fairly steady: 80.4% 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 10 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights80.4%
Oct–Dec 202591 flights89.0%
Jan–Mar 202690 flights90.0%
Apr–Jun 202685 flights83.5%

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, OO 5978 ranged from 80.4% on Monday to 90.0% on Thursday. With about 51 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.

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 3,753 reported delay minutes.

Carrier
31%
National Airspace System
24%
Late-arriving aircraft
23%
Extreme weather
21%

Extreme weather accounts for 21% 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 3.4 times the usual weather exposure. The split is drawn from 3,753 delay minutes reported on OO 5978.

Cancellations are rare at 0.00%, below the national 1.81% 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 8.1% 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

Every one of the 358 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. 358 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: 85.8% on time and 0.00% cancelled. That is a base rate, not a promise about any single day.

Where to go next

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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures