Route on-time record
ISP to BWI: most on-time flights and the best time to fly
Islip (Long Island MacArthur Airport) to Baltimore (Baltimore/Washington International Thurgood Marshall Airport). 1,201 nonstop flights in Jun 2025 to May 2026, 84% arrived within 15 minutes and 1.4% were cancelled. The most reliable flight number was Southwest 2160 at 6:00 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
ISP → BWI
Islip to Baltimore: 1,201 nonstop flights a year
On time (12 months)
84%
Cancelled
1.4%
avg delay 11 min
Best time to leave
Before 9 AM
96% on time vs 77% noon to 3 PM
Most reliable airline
Southwest
83% chance on time
Fares open on our travel partner (Aviasales). Pick the flight number you chose here.
Most reliable nonstop flights
Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.
#1 · Southwest 2160
6:00 AM → 7:20 AM1h 20m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 1187; its record covers all of them.
95%
chance on time
- On time (history)
- 99%
- Cancelled
- 1.1%
- Avg arrival delay
- 5 min
- Arrived on time 99% of the time (87 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 96% on time; Noon to 3 PM: 77%).
Moderate track record · 87 flights
Find Southwest 2160 fares Opens this date on Aviasales#2 · Southwest 1076
9:00 AM → 10:20 AM1h 20m nonstop
Local times, typical schedule. Last flown 2026-05-27.
90%
chance on time
- On time (history)
- 100%
- Cancelled
- 0.0%
- Avg arrival delay
- 1 min
- Arrived on time 100% of the time (16 flights, Jun 2025 to May 2026).
- Short track record (16 flights), so its score leans on the airline's record at this hour.
Limited track record · 16 flights
Find Southwest 1076 fares Opens this date on Aviasales#3 · Southwest 1077
8:35 AM → 9:55 AM1h 20m nonstop
Local times, typical schedule. Last flown 2026-05-29.
88%
chance on time
- On time (history)
- 96%
- Cancelled
- 0.0%
- Avg arrival delay
- 3 min
- Arrived on time 96% of the time (23 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 96% on time; Noon to 3 PM: 77%).
- Short track record (23 flights), so its score leans on the airline's record at this hour.
Limited track record · 23 flights
Find Southwest 1077 fares Opens this date on Aviasales#4 · Southwest 3215
4:40 PM → 6:00 PM1h 20m nonstop
Local times, typical schedule. Last flown 2026-05-30.
86%
chance on time
- On time (history)
- 100%
- Cancelled
- 0.0%
- Avg arrival delay
- 1 min
- Arrived on time 100% of the time (8 flights, Jun 2025 to May 2026).
- Lands inside BWI's trouble window: 81% of its 43 ground stops and delay programs started between 2 PM and 8 PM.
- Short track record (8 flights), so its score leans on the airline's record at this hour.
Limited track record · 8 flights
Find Southwest 3215 fares Opens this date on Aviasales#5 · Southwest 1257
4:30 PM → 5:50 PM1h 20m nonstop
Local times, typical schedule. Last flown 2026-05-29.
85%
chance on time
- On time (history)
- 91%
- Cancelled
- 0.0%
- Avg arrival delay
- 5 min
- Arrived on time 91% of the time (23 flights, Jun 2025 to May 2026).
- Lands inside BWI's trouble window: 81% of its 43 ground stops and delay programs started between 2 PM and 8 PM.
- Short track record (23 flights), so its score leans on the airline's record at this hour.
Limited track record · 23 flights
Find Southwest 1257 fares Opens this date on Aviasales#6 · Southwest 3081
12:30 PM → 1:45 PM1h 15m nonstop
Local times, typical schedule. Last flown 2026-05-29.
82%
chance on time
- On time (history)
- 87%
- Cancelled
- 0.0%
- Avg arrival delay
- 6 min
- Arrived on time 87% of the time (39 flights, Jun 2025 to May 2026).
- Never cancelled in 39 scheduled flights.
- Leaves in this route's least on-time window (Noon to 3 PM: 77% on time; Before 9 AM: 96%).
- Short track record (39 flights), so its score leans on the airline's record at this hour.
Limited track record · 39 flights
Find Southwest 3081 fares Opens this date on Aviasales#7 · Southwest 993
4:10 PM → 5:30 PM1h 20m nonstop
Local times, typical schedule. Last flown 2026-05-31.
81%
chance on time
- On time (history)
- 84%
- Cancelled
- 0.0%
- Avg arrival delay
- 13 min
- Arrived on time 84% of the time (32 flights, Jun 2025 to May 2026).
- Never cancelled in 32 scheduled flights.
- Lands inside BWI's trouble window: 81% of its 43 ground stops and delay programs started between 2 PM and 8 PM.
- 74% of its delay minutes came from the plane arriving late from an earlier flight.
Limited track record · 32 flights
Find Southwest 993 fares Opens this date on Aviasales#8 · Southwest 2939
5:55 PM → 7:15 PM1h 20m nonstop
Local times, typical schedule. Last flown 2026-04-05.
73%
chance on time
- On time (history)
- 66%
- Cancelled
- 6.3%
- Avg arrival delay
- 15 min
- Arrived on time 66% of the time (29 flights, Jun 2025 to May 2026).
- Cancelled 6.3% of the time (2 of 32).
- Lands inside BWI's trouble window: 81% of its 43 ground stops and delay programs started between 2 PM and 8 PM.
- 85% of its delay minutes came from the plane arriving late from an earlier flight.
Limited track record · 29 flights
Find Southwest 2939 fares Opens this date on Aviasales#9 · Southwest 1744
2:00 PM → 3:15 PM1h 15m nonstop
Local times, typical schedule. Last flown 2026-04-06.
69%
chance on time
- On time (history)
- 57%
- Cancelled
- 0.0%
- Avg arrival delay
- 23 min
- Arrived on time 57% of the time (23 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (Noon to 3 PM: 77% on time; Before 9 AM: 96%).
- Lands inside BWI's trouble window: 81% of its 43 ground stops and delay programs started between 2 PM and 8 PM.
- 52% of its delay minutes came from the plane arriving late from an earlier flight.
Limited track record · 23 flights
Find Southwest 1744 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Southwest Airlines83%
1,201 flights · 84% on time as flown · 1.4% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM96%
391 flights · avg delay 4 min
- 9 AM to noon87%
159 flights · avg delay 5 min
- Noon to 3 PM77%
289 flights · avg delay 15 min
- 3 to 6 PM78%
355 flights · avg delay 20 min
Best day: Tuesday (88%). Worst: Friday (83%).
On time by month
All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.
What delays this route
- Late-arriving aircraft43%
- Air traffic control and airport volume33%
- Airline (crew, maintenance, boarding)23%
Share of delay minutes by the cause airlines report to the US DOT.
Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure
ISP to BWI questions
- What time of day is best to fly ISP to BWI?
- Before 9 AM: 96% of flights arrived on time, against 77% for departures noon to 3 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
- Which airline is most on time from ISP to BWI?
- Southwest, with a season-adjusted 83% chance of operating and arriving on time over 1,201 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
- What is the worst month for delays on ISP to BWI?
- July (75% on time); the best was September (94%), averaged over Jun 2023 to May 2026.
- Is this a prediction for my flight?
- No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.
More routes from ISP
- BWI to ISP (return)
- ISP to MCO 72%
- ISP to PBI 71%
- ISP to TPA 71%
- ISP to FLL 68%
Live status: FAA delays and ground stops
