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DelayAtlas

Route reliability record

GSPORD

Greer to Chicago

Flights
1,797
Period
July 2025 to June 2026
Distance
577 mi
Carriers
6
C−GRADE

This route carries a cancellation problem, not just a delay problem: 3.8% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, close to three flights in four arrive on time, worth a C− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 1,797 GSP to ORD flights, of which Envoy Air flew 775 at 72.5% on time.

Best time to fly GSP to ORD: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 86.3% of the time and Wednesday flights 80.2%, against 74.9% for the route overall.

The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

Key figures

On time

74.9%

Arrivals under 15 minutes late, of 1,718 completed flights

Avg delay

73 min

Across delayed arrivals only, not all flights

Cancelled

3.84%

National rate is 1.81%

Best carrier

Envoy

72.5% on time across 775 flights

These figures cover 1,797 flights between July 2025 and June 2026. Beyond the headline rate, 8.9% 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

Which airline is most reliable on GSP to ORD

The two carriers here are closely matched: 2 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

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 Airlines52770.4%83 min4.74%C−

SkyWest Airlines cancels 4.7% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

Best ways to make this trip

The most reliable ways to fly Greer to Chicago

Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 2 of the top 4 use a different airport at one end.

Most reliable ways to fly from GSP to ORD
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. AVLORDAsheville to ChicagoEnvoy Air70.2%72.3%2.90%5am–8am, Wed
2. GSPORDGreer to ChicagoEnvoy Air70.0%72.5%3.48%5am–8am, Wed
3. AVLORDAsheville to ChicagoSkyWest Airlines69.8%71.6%2.57%5am–8am, Fri
4. GSPORDGreer to ChicagoSkyWest Airlines67.1%70.4%4.74%5am–8am, Mon

Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.

Plan this trip by month, day and time

Departure window

The best time of day to leave

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 32 points, against 2 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am452 flights86.3%
  • 8am–11am340 flights82.3%
  • 11am–2pm362 flights81.8%
  • 2pm–5pm26 flights
  • 5pm–8pm441 flights54.0%
  • 8pm–5am176 flights66.7%

Scale runs 45% to 90%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 54.0% on time, against 86.3% 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 5am–8am window is the busiest, with 452 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 27 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.

On-time rate by calendar month63J75F74M81A83M74J62J82A88S81O72N61D
Darker means more delays. Figures are on-time percentages.September best, December worst

December is the weak month at 61.4% on time, against 88.1% in September. 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 184 flights.

Across the week, Wednesday is the strongest day at 80.2% on time and Sunday the weakest at 70.4%. 10 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week78.8Mon76.0Tue80.2Wed72.1Thu71.5Fri75.5Sat70.4Sun
Monday: 78.8 percent on time. Tuesday: 76.0 percent on time. Wednesday: 80.2 percent on time. Thursday: 72.1 percent on time. Friday: 71.5 percent on time. Saturday: 75.5 percent on time. Sunday: 70.4 percent on time

Delay causes

Why this route gets delayed

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 31,000 reported delay minutes.

  • Late-arriving aircraft
    33%
  • National Airspace System
    31%
  • Carrier
    27%
  • Extreme weather
    9%
  • Security
    0%

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 86.3% on time here. The split is drawn from 31,489 reported delay minutes.

No single cause dominates. late-arriving aircraft at 33%, national airspace system at 31% and carrier at 27% split the 31,000 reported delay minutes between them. An even spread like this usually means the operation is running close to its designed capacity with no one obvious weak point, and it is the hardest pattern for a traveller to route around.

Cancellations run at 3.84%, against 1.81% nationally. That is about one flight in 25 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 actually costs

8.9% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.

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 72.9% on time across 1,799 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 1,797 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

Work out the risk of missing a connection in ORD after this flight

What to do with this

Booking this route

Put together: the delay figures matter less here than the 3.84% cancellation rate. A late arrival costs you a little over an hour; 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. 1,718 completed flights over 12 months sit behind that.

Common questions

GSP to ORD questions

How often is GSP to ORD delayed?

About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.1% of the 1,797 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

Which airline is most reliable on GSP to ORD?

Envoy Air leads at 72.5% on time across 775 flights. SkyWest Airlines is at the other end on 70.4%, a gap of 2 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

What time of day has the fewest delays on GSP to ORD?

The 5am–8am departure window is the strongest at 86.3% on time. The 5pm–8pm window is the weakest at 54.0%, 32 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.

How bad are December delays on GSP to ORD?

December is the weakest month at 61.4% on time, compared with 88.1% in September. Across the year that is 27 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Related

Where to go next

Direction matters. GSP to ORD and ORD to GSP are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Embed GSP to ORD’s on-time badge on your site

Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.

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.