79% of flights leaving Greer (GSP) arrived on time over the past 12 months, 3 points better than the national average of 76%. About 54 flights leave GSP on a typical day; 2.9% were cancelled. 79% pushed back from the gate on time, so most of the lateness is already there when the flight leaves the gate.
At a glance
- Best hour to fly: 5 a.m. (93% on time). Worst: 8 p.m. (60%).
- Best month: October (86%). Worst: July (70%).
- Most reliable airline here: Southwest Airlines (86%), vs American Airlines at 76%.
- Biggest delay cause: late-arriving aircraft (45% of delay minutes).
- Year on year: about the same (79% → 79%).
How late?
The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for flights leaving GSP: when a flight was late, it was under 45 minutes late 47% of the time. About 1 in 13 flights landed an hour or more late, and 1 in 50 three hours or more; 2.9% were cancelled outright.
- On time or early79%
- 15–30 min late5.6%
- 30–60 min late4.8%
- 1–2 hours late4.0%
- 2–3 hours late1.7%
- 3+ hours late2.0%
- Diverted0.3%
- Cancelled2.9%
Share of all 19,855 scheduled flights, past 12 months, by arrival time against schedule.
Best time of day to fly out of GSP
Time of day matters more at GSP than almost anything else you control. Flights scheduled to leave at 5 a.m. arrived on time 93% of the time; at 8 p.m. it was 60%, a 33-point gap. Taken together, early departures (5–9 a.m.) ran 86% on time against 65% for the evening bank (5–10 p.m.). Early planes usually start the day at the airport, so they haven't had a chance to pick up delays elsewhere. By evening a late inbound aircraft, a crew running out of duty hours or an afternoon thunderstorm can push one late flight into the next. Cancellations cluster too: 7 p.m. departures were cancelled 5.8% of the time, against 2.9% overall.
Hour × month
Combine the two and the spread is wider still. The most reliable combination at GSP was a 6 a.m. departure in October (95% on time); the least, 6 p.m. in July (46%). If you can only move one thing, move the hour. Departure hour usually shifts the odds more than the month does.
Each cell: on-time rate for that departure hour in that calendar month, 2023–2026. Find your travel month, then look along the row for the greenest hour.
Best and worst months
July is the hardest month at GSP, with 70% of flights on time across 2023–2026; October is the best at 86%. Summer (June–August) runs 11 points worse than autumn: heavy schedules, peak loads and afternoon thunderstorms. Winter costs 5 points against autumn. Cancellations peak in January (5.7% of flights).
Airlines at GSP
American Airlines runs 45% of departures from GSP. Among airlines with at least 1,000 departures here, Southwest Airlines was the most reliable (86% on time) and American Airlines the least (76%), a 10-point difference. On a route where both fly, that difference is worth more than a small fare gap.
| Airline | Departures | On time | Left on time | Cancelled | Typical arrival |
|---|---|---|---|---|---|
| American Airlines | 8,877 | 76% | 76% | 3.1% | −8 min |
| Delta Air Lines | 4,947 | 82% | 81% | 3.3% | −13 min |
| United Airlines | 3,933 | 80% | 83% | 3.0% | −10 min |
| Southwest Airlines | 1,596 | 86% | 81% | 1.1% | −9 min |
| Allegiant Air | 502 | 58% | 60% | 0.8% | +6 min |
Why flights are late at GSP
Airlines report a cause for every flight that arrives 15 or more minutes late. At GSP, 45% of delay minutes came from late-arriving aircraft: the plane showed up late from its previous flight, so the delay started somewhere else. Next is the airlines themselves at 28%. That's why the first flight of the morning is the safest bet: it has no earlier flight to inherit a delay from. Of the 582 cancellations, 60% were blamed on weather.
The average taxi from gate to takeoff is 17 minutes, about typical for a large U.S. airport.
GSP vs nearby airports
| Airport | Distance | Departures | On time | Cancelled |
|---|---|---|---|---|
| GSP Greenville-Spartanburg | — | 19,855 | 79% | 2.9% |
| AVL Asheville | 42 mi | 13,647 | 75% | 2.5% |
Month by month
Over the latest 12 months 79% of GSP departures were on time, against 79% in the 12 months before: essentially unchanged. The best recent month was September 2025 (88%); the worst, July 2026 (70%).
Worst cancellation days
The worst single day in the past year was Sunday, Jan 25, 2026, when 100% of 51 scheduled departures were cancelled. Days like that are usually a major storm, a system outage or a holiday peak hitting bad weather. No average predicts them, so on a stormy forecast, check your airline's travel waivers.
| Date | Departures | Cancelled | On time |
|---|---|---|---|
| Jan 25, 2026 | 51 | 100% | 0% |
| Jan 31, 2026 | 38 | 66% | 18% |
| Jan 26, 2026 | 50 | 56% | 18% |
| Feb 1, 2026 | 51 | 33% | 43% |
| Mar 16, 2026 | 55 | 27% | 29% |
| Jan 27, 2026 | 46 | 26% | 41% |
| Feb 23, 2026 | 52 | 25% | 65% |
| Nov 9, 2025 | 59 | 20% | 53% |
| Aug 7, 2026 | 58 | 19% | 59% |
| Jul 21, 2026 | 58 | 19% | 62% |
Last flights of the day
The last flight of the day is a different bet. Across routes from GSP, each airline's final departure was cancelled 4.5% of the time, against 2.5% for its earlier flights (1.8× as often). Late in the day crews run short on duty hours, aircraft arrive late from elsewhere, and with no later flight to fold passengers into, cancelling is easier for the airline. 2.4% of last flights landed 3+ hours late. The riskiest last flight out was American Airlines to Washington (9.7% cancelled).
| Last flight to | Airline | Leaves | Cancelled | 3h+ late | On time |
|---|---|---|---|---|---|
| DCA Washington | American Airlines | 7:14 p.m. | 9.7% | 3.6% | 49% |
| LGA New York | American Airlines | 5:58 p.m. | 8.8% | 3.7% | 60% |
| LGA New York | Delta Air Lines | 6:07 p.m. | 10.1% | 2.2% | 56% |
| EWR Newark | United Airlines | 7:49 p.m. | 8.5% | 3.0% | 74% |
| ORD Chicago | American Airlines | 6:38 p.m. | 7.0% | 2.0% | 61% |
| ORD Chicago | United Airlines | 5:43 p.m. | 5.2% | 2.8% | 55% |
| DTW Detroit | Delta Air Lines | 6:55 p.m. | 2.8% | 4.0% | 73% |
| PHL Philadelphia | American Airlines | 6:31 p.m. | 3.3% | 3.0% | 81% |
| IAD Washington | United Airlines | 7:40 p.m. | 2.6% | 2.9% | 77% |
| DFW Dallas | American Airlines | 7:55 p.m. | 3.6% | 1.9% | 66% |
| ATL Atlanta | Delta Air Lines | 5:20 p.m. | 2.2% | 1.9% | 81% |
| BWI Baltimore | Southwest Airlines | 1:55 p.m. | 1.7% | 1.4% | 82% |
Each airline's last scheduled departure of the day on a route, on days it flies the route at least twice; past 12 months. Riskiest first.
Tips for flying out of GSP
- Book the earliest departure you can live with. At GSP the 5 a.m. flights do best.
- Traveling in July? Leave extra slack for anything that can't move: cruises, weddings, the last connection of the day.
- Choosing between airlines? Southwest Airlines has the better record here.
- Need to arrive tonight? Don't book the last flight out of GSP; the one before it leaves you a backup.
- Delayed already? Most delays at GSP come from late-arriving aircraft. If your inbound plane is late, your flight will be too, whatever the board says.
Routes from GSP
Where you're going matters too. From GSP, the most reliable busy route was to Atlanta (ATL, 89% on time) and the least reliable to New York (LGA, 70%). Flights into congested airports inherit their delays: an air traffic program at the destination holds planes on the ground here.
Least reliable first. Routes with at least 365 flights a year.
| To | Flights | On time | Cancelled | Typical arrival |
|---|---|---|---|---|
| DCA Washington | 999 | 61% | 5.5% | +2 min |
| LGA New York | 2,165 | 70% | 7.0% | −7 min |
| ORD Chicago | 2,131 | 72% | 3.7% | −6 min |
| DFW Dallas | 1,175 | 74% | 2.5% | −6 min |
| MIA Miami | 723 | 78% | 1.2% | −6 min |
| EWR Newark | 893 | 82% | 5.5% | −14 min |
| DTW Detroit | 889 | 82% | 2.4% | −13 min |
| CLT Charlotte | 2,986 | 82% | 2.2% | −11 min |
| IAD Washington | 856 | 83% | 1.8% | −10 min |
| PHL Philadelphia | 1,095 | 83% | 2.5% | −15 min |
| BNA Nashville | 730 | 83% | 0.4% | −7 min |
| IAH Houston | 673 | 87% | 1.2% | −17 min |
| BWI Baltimore | 719 | 88% | 1.7% | −9 min |
| ATL Atlanta | 2,805 | 89% | 1.6% | −15 min |
Flights into GSP
Arriving rather than leaving? These are the routes into Greenville-Spartanburg, least reliable first. The weakest is from Washington (61% on time).
| From | Flights | On time | Cancelled |
|---|---|---|---|
| DCA Washington | 999 | 61% | 5.2% |
| LGA New York | 2,165 | 67% | 7.1% |
| BNA Nashville | 730 | 70% | 0.7% |
| DFW Dallas | 1,173 | 71% | 2.3% |
| ORD Chicago | 2,133 | 72% | 3.6% |
| DTW Detroit | 890 | 72% | 2.3% |
| PHL Philadelphia | 1,096 | 76% | 2.8% |
| CLT Charlotte | 2,986 | 77% | 1.7% |
| EWR Newark | 893 | 78% | 6.5% |
| MIA Miami | 724 | 78% | 1.2% |
| IAD Washington | 855 | 79% | 1.5% |
| BWI Baltimore | 720 | 79% | 1.8% |
| ATL Atlanta | 2,804 | 82% | 1.6% |
| IAH Houston | 673 | 84% | 0.9% |
Questions about GSP delays
What is the best time to fly out of GSP?
Flights scheduled at 5 a.m.: over the past year 93% of GSP departures at that hour arrived on time, against 60% at 8 p.m., the worst hour.
What month has the most flight delays at GSP?
July (70% on time). October is the best month (86%).
Which airline is most on time at GSP?
Southwest Airlines: 86% of its GSP departures arrived on time over the past year. American Airlines had the weakest record at 76%.
Why are flights delayed at GSP?
The biggest cause was late-arriving aircraft (45% of delay minutes): the plane showed up late from its previous flight, so the delay started somewhere else. Then the airlines themselves (28%).
How often are flights cancelled at GSP?
2.9% of scheduled departures over the past 12 months, peaking in January at 5.7%.
Hours are scheduled local departure times. "On time" means arriving less than 15 minutes late at the destination; cancelled and diverted flights count as not on time. Method.