Carrier route record
UAORD→PBI
United Airlines · Chicago to West Palm Beach
- Flights
- 502
- Period
- July 2025 to June 2026
- Share of route
- 39%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on ORD to PBI sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 502 flights, with a median arrival 1 minute early.
The national on-time rate over the same period is 77.6%, so United on ORD to PBI runs 4 points behind the country as a whole. Across a thousand flights that is about 41 extra late arrivals.
Key figures
On time
73.5%
Arrivals under 15 minutes late, of 498 completed flights
Avg delay
67 min
Across delayed arrivals only, not all flights
Cancelled
0.40%
National rate is 1.81%
Whole route
68.9%
Every carrier on ORD to PBI, 1,298 flights
These figures cover 502 flights between July 2025 and June 2026. Beyond the headline rate, 9.8% 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
United against every carrier on ORD to PBI
United flew 502 of the 1,298 flights on ORD to PBI, about 39% of it. Its 73.5% on time is 5 points better than the route as a whole, which runs 68.9%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 73.5% to American at 66.0%.
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 |
|---|---|---|---|---|---|
| United Airlines (this page) | 502 | 73.5% | 67 min | 0.40% | C+ |
| American Airlines | 796 | 66.0% | 85 min | 2.51% | C |
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 14 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–8am78 flights79.5%
- 8am–11am95 flights65.6%
- 11am–2pm204 flights74.4%
- 2pm–5pm125 flights74.2%
- 5pm–8pm—
- 8pm–5am—
Scale runs 55% to 85%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 79.5% of the time, against 65.6% for the morning window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 204 flights scheduled in it.
Across the year
United on ORD to PBI through the year
May is the best month on the calendar at 78.6% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. March was the busiest month here, with 90 flights.
Across the week, Tuesday is the strongest day at 79.4% on time and Friday the weakest at 66.2%. 13 points is a smaller lever than departure hour, but it is free.
Delay causes
Why United runs late on this route
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 8,815 reported delay minutes.
- 40%Late-arriving aircraft
- 37%National Airspace System
- 18%Carrier
- 5%Extreme weather
40% 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 8,815 reported delay minutes here, that single category outweighs weather by 8 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 8,815 reported delay minutes.
37% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 3,236 minutes out of 8,815, against a national NAS share of 21%.
Cancellations are rare at 0.40%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
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. 9.8% 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 1,144 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 66.5% on time across 501 flights, 7 points below 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 7 points of difference.
One caution: this is a thin sample. 502 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 ORD to PBI
Put together: treat all of this as provisional. 502 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 73.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 498 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.