Best Time to Fly GSP to BWI: On-Time Stats by Hour & Airline
Greenville-Spartanburg International → Baltimore/Washington International Thurgood Marshall
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 90.1% of Greer (GSP) to Baltimore (BWI) flights arrived on time (719 scheduled flights). That is 12.5 points above the national average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
January has been the best month (92% on time) and Monday the weakest day of the week (80%).
1.5% of flights were cancelled, versus 1.8% nationally.
GSP to BWI on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Southwest Airlines | 90.1% | 60 min | 1.5% | 719 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly GSP to BWI
On-time arrival % by scheduled departure hour (local time), 1,415 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | Limited data | 26 | |
| 6am–7am | 96.2% | 0.0% | 53 |
| 7am–8am | 94.0% | 1.6% | 322 |
| 8am–9am | 95.0% | 1.4% | 281 |
| 9am–10am | Limited data | 18 | |
| 10am–11am | Limited data | 28 | |
| 11am–12pm | Limited data | 1 | |
| 12pm–1pm | Limited data | 9 | |
| 1pm–2pm | 85.5% | 0.0% | 180 |
| 2pm–3pm | Limited data | 12 | |
| 3pm–4pm | 76.9% | 1.5% | 66 |
| 4pm–5pm | 84.5% | 3.3% | 60 |
| 5pm–6pm | 60.4% | 1.0% | 103 |
| 6pm–7pm | 79.5% | 1.8% | 114 |
| 7pm–8pm | 55.8% | 1.9% | 53 |
| 8pm–9pm | 60.2% | 1.1% | 89 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on GSP to BWI
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | Limited data | 26 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 78.0% | -10.1 pts | 1.7% | 60 |
| Summer peak (Jun 15 - Aug 15) | 74.2% | -13.9 pts | 1.2% | 248 |
| All other days | 88.1% | — | 1.3% | 1,081 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).