Route reliability record
EYW→ORD
Key West to Chicago
- Flights
- 717
- Period
- July 2025 to June 2026
- Distance
- 1,251 mi
- Carriers
- 3
This route draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is an hour and a half behind schedule. Build slack into anything you connect to. That rests on 717 EYW to ORD flights, with a median arrival 1 minute early.
Best time to fly EYW to ORD: a 5am–8am departure, ideally on a Monday. Flights in that window arrived on time 83.9% of the time and Monday flights 70.1%, against 67.4% for the route overall.
The national on-time rate over the same period is 77.6%, so this route runs 10 points behind the country as a whole. Across a thousand flights that is about 102 extra late arrivals.
Key figures
On time
67.4%
Arrivals under 15 minutes late, of 688 completed flights
Avg delay
93 min
Across delayed arrivals only, not all flights
Cancelled
1.39%
National rate is 1.81%
Best carrier
Envoy
67.0% on time across 407 flights
These figures cover 717 flights between July 2025 and June 2026. Beyond the headline rate, 13.8% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on EYW to ORD
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 |
|---|---|---|---|---|---|
| Republic Airwaysthin sample | 172 | 79.4% | 81 min | 1.74% | B |
| Envoy Air | 407 | 67.0% | 90 min | 1.23% | C |
| United Airlinesthin sample | 138 | 54.5% | 105 min | 1.45% | F |
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 20 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am33 flights83.9%
- 8am–11am1 flights—
- 11am–2pm221 flights71.6%
- 2pm–5pm336 flights63.8%
- 5pm–8pm126 flights65.3%
- 8pm–5am—
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 83.9% of the time, against 63.8% for the afternoon window. That is 20 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 336 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 28 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
February is the weak month at 56.8% on time, against 85.0% in May. 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. March was the busiest month here, with 114 flights.
Across the week, Monday is the strongest day at 70.1% on time and Sunday the weakest at 63.6%. 6 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 21,000 reported delay minutes.
- 39%Late-arriving aircraft
- 29%Carrier
- 25%National Airspace System
- 6%Extreme weather
- 0%Security
39% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 21,000 reported delay minutes here, that single category outweighs weather by 6 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 20,757 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 83.9% on time here.
Cancellations sit at 1.39% against a national 1.81%, which is ordinary. Diversions add another 2.65%.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 13.8% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
The 1,251 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 80.5% on time across 717 flights, 13 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 13 points of difference.
One caution: this is a thin sample. 717 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.
Work out the risk of missing a connection in ORD after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 717 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 67.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 688 completed flights over 12 months sit behind that.
Common questions
EYW to ORD questions
How often is EYW to ORD delayed?
About one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 32.6% of the 717 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is EYW to ORD compared with the rest of the country?
67.4% of flights arrive on time here against a national 77.6%, a difference of 10 points against it. That is worth a C on this site's grading scale.
What time of day has the fewest delays on EYW to ORD?
The 5am–8am departure window is the strongest at 83.9% on time. The 2pm–5pm window is the weakest at 63.8%, 20 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are February delays on EYW to ORD?
February is the weakest month at 56.8% on time, compared with 85.0% in May. Across the year that is 28 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- ORD to EYW — the return legseparate record
- Chicago O'Hare International (ORD) delay statistics
- Republic Airways on EYW to ORD79.4%
- Envoy Air on EYW to ORD67.0%
- United Airlines on EYW to ORD54.5%
- EYW to ATL, a related route85.7%
- LGA to ORD, a related route67.3%
- EYW to CLT, a related route82.9%
- Republic Airways on-time record79.4%
- Envoy Air on-time record67.0%
- United Airlines on-time record54.5%
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
Direction matters. EYW to ORD and ORD to EYW are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.