Best Time to Fly BWI to ISP: On-Time Stats by Hour & Airline
Baltimore/Washington International Thurgood Marshall → Long Island MacArthur
Data through July 2026 · Last updated October 18, 2026
1,236 flights were scheduled from Baltimore (BWI) to Islip (ISP) in the last 12 months, and 78.3% of those that flew arrived on time, 0.7 points above the US average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
Over 24 months, Tuesday was the most reliable day (83% on time) and July the worst month (69%).
The cancellation rate was 1.9% (US average 1.8%).
BWI to ISP 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 | 78.3% | 50 min | 1.9% | 1,236 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly BWI to ISP
On-time arrival % by scheduled departure hour (local time), 2,438 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | Limited data | 16 | |
| 7am–8am | Limited data | 25 | |
| 8am–9am | 100.0% | 0.0% | 47 |
| 9am–10am | 88.8% | 1.0% | 99 |
| 10am–11am | 85.4% | 0.7% | 464 |
| 11am–12pm | 89.1% | 0.0% | 147 |
| 12pm–1pm | 84.1% | 0.0% | 69 |
| 1pm–2pm | 75.6% | 1.1% | 88 |
| 2pm–3pm | 85.3% | 0.6% | 159 |
| 3pm–4pm | 81.7% | 3.5% | 199 |
| 4pm–5pm | 68.0% | 1.5% | 203 |
| 5pm–6pm | 68.8% | 1.2% | 81 |
| 6pm–7pm | Limited data | 13 | |
| 7pm–8pm | 61.5% | 3.0% | 99 |
| 8pm–9pm | 79.5% | 0.0% | 146 |
| 9pm–10pm | 74.9% | 2.3% | 261 |
| 10pm–11pm | 55.4% | 2.5% | 322 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on BWI to ISP
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) | 73.8% | -6.3 pts | 0.0% | 42 |
| Christmas & New Year (Dec 20 - Jan 3) | 64.0% | -16.0 pts | 1.1% | 90 |
| Summer peak (Jun 15 - Aug 15) | 68.3% | -11.7 pts | 2.9% | 515 |
| All other days | 80.1% | — | 1.1% | 1,791 |
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).