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DelayAtlas

Carrier route record

OOGSPORD

SkyWest Airlines · Greer to Chicago

Flights
527
Period
July 2025 to June 2026
Share of route
29%
Carriers
6
C−GRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with SkyWest Airlines.

SkyWest on GSP to ORD sits in the middle of the pack with a C−. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 527 flights, with a median arrival right on schedule.

The national on-time rate over the same period is 77.6%, so SkyWest on GSP to ORD runs 7 points behind the country as a whole. Across a thousand flights that is about 72 extra late arrivals.

Key figures

On time

70.4%

Arrivals under 15 minutes late, of 500 completed flights

Avg delay

83 min

Across delayed arrivals only, not all flights

Cancelled

4.74%

National rate is 1.81%

Whole route

74.9%

Every carrier on GSP to ORD, 1,797 flights

These figures cover 527 flights between July 2025 and June 2026. Beyond the headline rate, 11.6% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

SkyWest against every carrier on GSP to ORD

SkyWest flew 527 of the 1,797 flights on GSP to ORD, about 29% of it. Its 70.4% on time is 5 points worse than the route as a whole, which runs 74.9%. Ranked by on-time rate it is last of six carriers on the route, where the range runs from United at 100.0% to SkyWest at 70.4%. Four of those carriers flew fewer than 365 flights here, so treat their positions as rough.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on GSP to ORD
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlinesthin sample1100.0%0.00%A+
Republic Airwaysthin sample31384.5%79 min2.88%B
PSA Airlinesthin sample12782.9%64 min2.36%B
American Airlinesthin sample5477.6%56 min9.26%B−
Envoy Air77572.5%66 min3.48%C−
SkyWest Airlines (this page)52770.4%83 min4.74%C−

Departure window

When SkyWest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 30 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am130 flights87.9%
  • 8am–11am67 flights83.1%
  • 11am–2pm28 flights
  • 2pm–5pm24 flights
  • 5pm–8pm278 flights57.8%
  • 8pm–5am

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 57.8% on time, against 87.9% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5pm–8pm window is the busiest, with 278 flights scheduled in it.

Across the year

SkyWest on GSP to ORD through the year

On-time rate by calendar month87J86F67MA78M68JJAS77O61N47D
Darker means more delays. Figures are on-time percentages.January best, December worst

December is the weak month at 46.7% on time, against 87.1% in January. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. May was the busiest month here, with 85 flights.

Across the week, Monday is the strongest day at 78.3% on time and Sunday the weakest at 64.9%. 13 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week78.3Mon69.9Tue75.0Wed68.1Thu65.4Fri73.0Sat64.9Sun
Monday: 78.3 percent on time. Tuesday: 69.9 percent on time. Wednesday: 75.0 percent on time. Thursday: 68.1 percent on time. Friday: 65.4 percent on time. Saturday: 73.0 percent on time. Sunday: 64.9 percent on time

Delay causes

Why SkyWest runs late on this route

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 12,000 reported delay minutes.

  • Carrier
    35%
  • National Airspace System
    31%
  • Late-arriving aircraft
    24%
  • Extreme weather
    10%

The largest share of delay minutes, 35%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 4,294 of the 12,000 delay minutes reported here. The split is drawn from 12,343 reported delay minutes.

Cancellations run at 4.74%, against 1.81% nationally. That is about one flight in twenty cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and stage length

What a delay here costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.6% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

The 577 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.

The return leg runs 69.7% on time across 528 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 527 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 SkyWest on GSP to ORD

Put together: the delay figures matter less here than the 4.74% cancellation rate. A late arrival costs you an hour and a half; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 500 completed flights over 12 months sit behind that.

Related

Where to go next

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.