Route reliability record
ORD→GSP
Chicago to Greer
- Flights
- 1,799
- Period
- July 2025 to June 2026
- Distance
- 577 mi
- Carriers
- 6
This route carries a cancellation problem, not just a delay problem: 4.0% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, about seven flights in ten 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 1,799 ORD to GSP flights, of which Envoy Air flew 778 at 76.7% on time.
Best time to fly ORD to GSP: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 84.6% of the time and Tuesday flights 77.6%, against 72.9% for the route overall.
The national on-time rate over the same period is 77.6%, so this route runs 5 points behind the country as a whole. Across a thousand flights that is about 47 extra late arrivals.
Key figures
On time
72.9%
Arrivals under 15 minutes late, of 1,724 completed flights
Avg delay
74 min
Across delayed arrivals only, not all flights
Cancelled
4.00%
National rate is 1.81%
Best carrier
Envoy
76.7% on time across 778 flights
These figures cover 1,799 flights between July 2025 and June 2026. Beyond the headline rate, 10.3% 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 ORD to GSP
The choice of carrier is not cosmetic here. Envoy Air arrives on time 76.7% of the time; SkyWest Airlines manages 69.7%. Sample sizes sit next to every figure, because a two-point gap across 528 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| Republic Airwaysthin sample | 312 | 80.2% | 86 min | 4.49% | B− |
| Envoy Air | 778 | 76.7% | 61 min | 3.34% | B− |
| SkyWest Airlines | 528 | 69.7% | 69 min | 3.60% | C− |
| American Airlinesthin sample | 54 | 59.2% | 53 min | 9.26% | D− |
| PSA Airlinesthin sample | 126 | 48.7% | 122 min | 6.35% | F− |
SkyWest Airlines cancels 3.6% 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 Chicago to Greer
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.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. ORD → AVLChicago to Asheville | Envoy Air | 79.6% | 81.4% | 2.25% | 8am–11am, Wed | — |
| 2. ORD → GSPChicago to Greer | Envoy Air | 74.1% | 76.7% | 3.34% | 8am–11am, Fri | — |
| 3. ORD → AVLChicago to Asheville | SkyWest Airlines | 68.5% | 70.1% | 2.30% | 5am–8am, Tue | — |
| 4. ORD → GSPChicago to Greer | SkyWest Airlines | 67.2% | 69.7% | 3.60% | 5am–8am, Thu | — |
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.
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 19 points, against 7 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am73 flights81.9%
- 8am–11am382 flights84.6%
- 11am–2pm38 flights70.3%
- 2pm–5pm501 flights71.3%
- 5pm–8pm631 flights67.7%
- 8pm–5am174 flights66.0%
Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 84.6% of the time, against 66.0% for the overnight window. That is 19 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 631 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 22 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.
July is the worst month at 62.4% on time, 22 points below April, the best at 84.3%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. May was the busiest month here, with 185 flights.
Across the week, Tuesday is the strongest day at 77.6% on time and Sunday the weakest at 68.4%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 35,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 44%Late-arriving aircraft
- 30%Carrier
- 18%National Airspace System
- 9%Extreme weather
44% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 35,000 reported delay minutes here, that single category outweighs weather by 5 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 34,721 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 84.6% on time here.
Cancellations run at 4.00%, 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
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.3% 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 74.9% on time across 1,797 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 1,799 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 GSP after this flight
What to do with this
Booking this route
Put together: the delay figures matter less here than the 4.00% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 8am–11am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 1,724 completed flights over 12 months sit behind that.
Common questions
ORD to GSP questions
How often is ORD to GSP 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 27.1% of the 1,799 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 ORD to GSP?
Envoy Air leads at 76.7% on time across 778 flights. SkyWest Airlines is at the other end on 69.7%, a gap of 7 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 ORD to GSP?
The 8am–11am departure window is the strongest at 84.6% on time. The 8pm–5am window is the weakest at 66.0%, 19 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 July delays on ORD to GSP?
July is the weakest month at 62.4% on time, compared with 84.3% in April. Across the year that is 22 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
- GSP to ORD — the return legseparate record
- Chicago O'Hare International (ORD) delay statistics
- Republic Airways on ORD to GSP80.2%
- Envoy Air on ORD to GSP76.7%
- SkyWest Airlines on ORD to GSP69.7%
- PSA Airlines on ORD to GSP48.7%
- ORD to LGA, a related route67.3%
- ATL to GSP, a related route83.9%
- ORD to BOS, a related route67.6%
- United Airlines on-time record100.0%
- Republic Airways on-time record80.2%
- Envoy Air on-time record76.7%
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
Direction matters. ORD to GSP and GSP to ORD are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.