Carrier route record
WNMCO→ISP
Southwest Airlines · Orlando to Islip
- Flights
- 665
- Period
- September 2025 to August 2026
- Share of route
- 46%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Southwest Airlines.
Southwest on MCO to ISP draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 50 minutes behind schedule. Build slack into anything you connect to. That rests on 665 flights, with a median arrival 3 minutes late.
The national on-time rate over the same period is 77.3%, so Southwest on MCO to ISP runs 10 points behind the country as a whole. Across a thousand flights that is about 100 extra late arrivals.
Key figures
On time
67.3%
Arrivals under 15 minutes late, of 654 completed flights
Avg delay
52 min
Across delayed arrivals only, not all flights
Cancelled
1.65%
National rate is 1.89%
Whole route
76.2%
Every carrier on MCO to ISP, 1,441 flights
These figures cover 665 flights between September 2025 and August 2026. Beyond the headline rate, 8.6% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Southwest against every carrier on MCO to ISP
Southwest flew 665 of the 1,441 flights on MCO to ISP, about 46% of it. Its 67.3% on time is 9 points worse than the route as a whole, which runs 76.2%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from JetBlue at 86.3% to Southwest at 67.3%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| JetBlue Airways | 416 | 86.3% | 69 min | 1.20% | A |
| Frontier Airlinesthin sample | 360 | 81.0% | 62 min | 2.22% | B |
| Southwest Airlines (this page) | 665 | 67.3% | 52 min | 1.65% | C |
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Departure window
When Southwest runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 43 points, against half a point between the best and worst carrier.
- 5am–8am33 flights97.0%
- 8am–11am190 flights83.5%
- 11am–2pm91 flights63.7%
- 2pm–5pm46 flights66.7%
- 5pm–8pm103 flights56.0%
- 8pm–5am202 flights54.3%
Scale runs 45% to 100%.
The 8pm–5am window is where this operation falls apart: 54.3% on time, against 97.0% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8pm–5am window is the busiest, with 202 flights scheduled in it.
Across the year
Southwest on MCO to ISP through the year
December is the weak month at 47.6% on time, against 87.2% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. May was the busiest month here, with 66 flights.
Across the week, Tuesday is the strongest day at 72.2% on time and Monday the weakest at 62.1%, a spread of 10 points.
Arrival by arrival
How late Southwest on MCO to ISP runs when it is late
The 214 late arrivals split 85 under half an hour, 73 between 30 and 60 minutes, and 56 an hour or more.
- 15+ min early68 flights10.4%
- Within 15 min372 flights56.9%
- 15–29 min late85 flights13.0%
- 30–59 min late73 flights11.2%
- 1–2 hours late37 flights5.7%
- 2+ hours late19 flights2.9%
Scale runs 0% to 100%.
Share of 654 completed flights by arrival against schedule.
46 of 222 late departures made up the time and arrived on time, 21% of them. In the other direction, 38 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at ISP.
The worst days
Worst days for Southwest on MCO to ISP
The latest arrival of the period was on 8 November 2025, 5 hours 43 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 8 November 2025 | 5 hours 43 minutes | Carrier |
| 15 June 2026 | 4 hours 48 minutes | Late-arriving aircraft |
| 16 March 2026 | 3 hours 39 minutes | Late-arriving aircraft |
| 26 December 2025 | 3 hours 28 minutes | Late-arriving aircraft |
| 6 August 2026 | 3 hours 18 minutes | Carrier |
Delay causes
Why Southwest runs late on this route
Late-arriving aircraft accounts for 49% of the 11,000 delay minutes carriers reported here, and the remaining four split what is left.
- 49%Late-arriving aircraft
- 34%Carrier
- 15%National Airspace System
- 2%Security
- 1%Extreme weather
49% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 11,000 reported delay minutes here, that single category outweighs weather by 49 to one. The split is drawn from 11,173 reported delay minutes.
The largest share of delay minutes, 34%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,844 of the 11,000 delay minutes reported here.
Cancellations sit at 1.65% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
8.6% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last roughly 50 minutes, which a normal layover absorbs.
The 971 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.
The return leg is a different operation and performs like one: it runs 72.8% on time across 666 flights, 6 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 6 points of difference.
One caution: this is a thin sample. 665 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Southwest on MCO to ISP
Put together: treat all of this as provisional. 665 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 67.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 654 completed flights over 12 months sit behind that.
Related
Where to go next
- MCO to ISP, every carrier
- Southwest on ISP to MCO, the return leg
- JetBlue Airways on MCO to ISP86.3%
- Frontier Airlines on MCO to ISP81.0%
- Southwest Airlines network-wide record
- Orlando International (MCO) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.