Flight number record

OO 5377

SkyWest Airlines · Denver to Gunnison

Route: DEN → GUC
Departs: 19:25
Flights: 321
Period: September 2025 to August 2026

Historical statistics for September 2025 to August 2026, not live status. For today’s OO 5377, 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 5377 sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.3%. The late ones land about 2.1 hours behind schedule. That rests on 321 flights, with a median arrival 3 minutes early.

The national on-time rate over the same period is 77.3%, so OO 5377 runs 6 points behind the country as a whole. Across a thousand flights that is about 56 extra late arrivals.

On time

71.7%

Arrivals under 15 minutes late, of 315 completed flights

Avg delay

125 min

Across delayed arrivals only, not all flights

Cancelled

1.56%

National rate is 1.89%

1 hour+ late

11.1%

National rate is 8.3%

These figures cover 321 flights between September 2025 and August 2026. Beyond the headline rate, 11.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.

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Schedule

When OO 5377 flies

OO 5377 flies DEN to GUC without a single fixed slot. Its most common scheduled departure was 19:25, used on 121 of 321 flights, with 19:15 (92 flights) and 19:10 (54 flights) next.

Departs 19:25121 flights37.7%
Departs 19:1592 flights28.7%
Departs 19:1054 flights16.8%

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 19:25 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and OO 5377 runs 4 points better at 71.7%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

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Against the route

OO 5377 next to DEN to GUC

Every carrier on DEN to GUC combined arrived on time 80.5% of the time across 994 flights, so OO 5377 is 9 points behind it. Across its whole network SkyWest Airlines managed 78.7%, which this flight trails by 7 points.

OO 5377 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 5377thin sample	321	71.7%	125 min	1.56%	C
All SkyWest Airlines on DEN–GUC	994	80.5%	93 min	0.80%	B+
All carriers on DEN–GUC	994	80.5%	93 min	0.80%	B+
SkyWest Airlines, whole network	855,406	78.7%	88 min	1.79%	B

Across the year

OO 5377 quarter by quarter

OO 5377 did not run the same all year. Its best quarter was Oct–Dec 2025 at 80.0% on time and its weakest Jul–Sep 2026 at 46.7%, a swing of 33 points on roughly 64 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 flights76.7%
Oct–Dec 202591 flights80.0%
Jan–Mar 202669 flights78.5%
Apr–Jun 202670 flights74.3%
Jul–Sep 202661 flights46.7%

Scale runs 40% to 85%.

By weekday, OO 5377 did best on Tuesday at 82.6% on time and worst on Monday at 66.0%. Each day rests on about 46 flights, so a gap of 17 points is worth noticing but could still narrow in another year.

Arrival by arrival

How late OO 5377 runs when it is late

The 89 late arrivals split 26 under half an hour, 28 between 30 and 60 minutes, and 35 an hour or more.

15+ min early68 flights21.6%
Within 15 min158 flights50.2%
15–29 min late26 flights8.3%
30–59 min late28 flights8.9%
1–2 hours late24 flights7.6%
2+ hours late11 flights3.5%

Scale runs 0% to 100%.

Share of 315 completed flights by arrival against schedule.

Time lost at the gate mostly stays lost. Of 72 departures that left 15 minutes late or more, only 5 made it up before arrival. In the other direction, 22 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 GUC.

The worst days

Worst days for OO 5377

The latest arrival of the period was on 15 August 2026, 17 hours 17 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.

The latest arrivals of OO 5377 in the period
Date	Arrived late by	Largest filed cause
15 August 2026	17 hours 17 minutes	Late-arriving aircraft
21 May 2026	14 hours 18 minutes	Late-arriving aircraft
22 July 2026	13 hours 46 minutes	Carrier
13 August 2026	13 hours 30 minutes	Late-arriving aircraft
16 September 2025	12 hours 10 minutes	National Airspace System

Delay causes

Why OO 5377 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 11,000 reported delay minutes.

Late-arriving aircraft
42%
Carrier
33%
National Airspace System
16%
Extreme weather
9%

42% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 11,000 reported delay minutes here, that single category outweighs weather by 4 to one. The split is drawn from 11,121 delay minutes reported on OO 5377.

Cancellations sit at 1.56% against a national 1.89%, which is ordinary. Diversions add another 0.31%.

Connections and routes

What a delay on this flight costs

11.1% 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 same number turns up on two other city pairs in the data, including SAF to DEN (155) and IAH to ICT (21), but none flew often enough under OO 5377 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DEN to GUC only.

One caution: this is a thin sample. 321 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 5377

For a booking, OO 5377 is one of the weaker ways to fly DEN to GUC: 9 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.

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, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures