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DelayAtlas

Carrier route record

UAEYWORD

United Airlines · Key West to Chicago

Flights
138
Period
July 2025 to June 2026
Share of route
19%
Carriers
3
FGRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.

United on EYW to ORD earns an F, which is as low as this site's scale goes for a reason. Only 54.5% of flights arrive inside the 15-minute window, 23 points worse than the national rate of 77.6%. Late arrivals average close to two hours. Treat any tight connection here as a coin flip. That rests on 138 flights, with a median arrival 12 minutes late.

The national on-time rate over the same period is 77.6%, so United on EYW to ORD runs 23 points behind the country as a whole. Across a thousand flights that is about 231 extra late arrivals.

Key figures

On time

54.5%

Arrivals under 15 minutes late, of 134 completed flights

Avg delay

105 min

Across delayed arrivals only, not all flights

Cancelled

1.45%

National rate is 1.81%

Whole route

67.4%

Every carrier on EYW to ORD, 717 flights

These figures cover 138 flights between July 2025 and June 2026. Beyond the headline rate, 19.4% 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

United against every carrier on EYW to ORD

United flew 138 of the 717 flights on EYW to ORD, about 19% of it. Its 54.5% on time is 13 points worse than the route as a whole, which runs 67.4%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Republic at 79.4% to United at 54.5%. 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.

On-time performance by carrier on EYW to ORD
AirlineFlightsOn timeAvg delayCancelledGrade
Republic Airwaysthin sample17279.4%81 min1.74%B
Envoy Air40767.0%90 min1.23%C
United Airlines (this page)thin sample13854.5%105 min1.45%F

Departure window

When United runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 138 flights.

There are not enough flights in each departure window to split United's EYW to ORD record by time of day without the percentages moving on noise. The headline rate of 54.5% is the reliable figure here.

Across the year

United on EYW to ORD through the year

  • Oct–Dec 202514 flights
  • Jan–Mar 202695 flights53.8%
  • Apr–Jun 202629 flights

Scale runs 45% to 60%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 54.5% on time across 138 flights.

Split by quarter, United on EYW to ORD logged 14 flights in Oct–Dec 2025, 95 flights in Jan–Mar 2026 and 29 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 54.5% annual figure is the one to use.

Delay causes

Why United runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 6,382 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

  • Late-arriving aircraft
    45%
  • Carrier
    33%
  • National Airspace System
    22%

45% 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 6,382 reported delay minutes here, that single category outweighs weather by 45 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 6,382 reported delay minutes.

Cancellations sit at 1.45% against a national 1.81%, which is ordinary. Diversions add another 1.45%.

Connections and stage length

What a delay here costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 19.4% 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 77.2% on time across 138 flights, 23 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 23 points of difference.

One caution: this is a thin sample. 138 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 United on EYW to ORD

Put together: treat all of this as provisional. 138 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 54.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 134 completed flights over 12 months sit behind that.

Related

Where to go next

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.