Flight number record
UA 2143
United Airlines · Newark to San Juan
- Route
- EWR → SJU
- Departs
- 07:55
- Flights
- 365
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s UA 2143, check with United Airlines.
UA 2143 sits in the middle of the pack with a C−. About seven flights in ten arrive on time by the DOT's definition, 8 points worse than the national rate of 77.6%. The late ones land close to two hours behind schedule. That rests on 365 flights, with a median arrival 6 minutes early.
The national on-time rate over the same period is 77.6%, so UA 2143 runs 8 points behind the country as a whole. Across a thousand flights that is about 76 extra late arrivals.
Key figures
On time
70.0%
Arrivals under 15 minutes late, of 350 completed flights
Avg delay
101 min
Across delayed arrivals only, not all flights
Cancelled
3.84%
National rate is 1.81%
1 hour+ late
12.3%
National rate is 8.1%
These figures cover 365 flights between July 2025 and June 2026. Beyond the headline rate, 12.3% 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.
Schedule
When UA 2143 flies
UA 2143 flies EWR to SJU without a single fixed slot. Its most common scheduled departure was 07:55, used on 205 of 365 flights, with 08:00 (150 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 07:55205 flights56.2%
- Departs 08:00150 flights41.1%
Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 07:55 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and UA 2143 runs 19 points worse at 70.0%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
Against the route
UA 2143 next to EWR to SJU
Every carrier on EWR to SJU combined arrived on time 70.7% of the time across 2,101 flights, so UA 2143 is about level with it. United flew 1,113 flights on the same city pair under all its flight numbers, including this one, and those ran 71.0% on time. Across its whole network United Airlines managed 79.0%, which this flight trails by 9 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 2143 | 365 | 70.0% | 101 min | 3.84% | C− |
| All United Airlines on EWR–SJU | 1,113 | 71.0% | 75 min | 2.34% | C |
| All carriers on EWR–SJU | 2,101 | 70.7% | 82 min | 2.95% | C |
| United Airlines, whole network | 821,041 | 79.0% | 72 min | 1.01% | B |
Across the year
UA 2143 quarter by quarter
UA 2143 did not run the same all year. Its best quarter was Apr–Jun 2026 at 80.0% on time and its weakest Oct–Dec 2025 at 51.8%, a swing of 28 points on roughly 91 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202592 flights74.2%
- Oct–Dec 202592 flights51.8%
- Jan–Mar 202690 flights73.3%
- Apr–Jun 202691 flights80.0%
Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.
By weekday, UA 2143 did best on Tuesday at 80.8% on time and worst on Monday at 57.1%. Each day rests on about 52 flights, so a gap of 24 points is worth noticing but could still narrow in another year.
Delay causes
Why UA 2143 runs late
One category carries most of the weight here. Carrier accounts for 54% of the 11,000 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.
- 54%Carrier
- 31%Late-arriving aircraft
- 13%National Airspace System
- 2%Extreme weather
The largest share of delay minutes, 54%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 5,733 of the 11,000 delay minutes reported here. The split is drawn from 10,554 delay minutes reported on UA 2143.
Cancellations run at 3.84%, against 1.81% nationally. That is about one flight in 25 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and routes
What a delay on this flight costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 12.3% 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.
At 1,608 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
Every one of the 365 flights under UA 2143 in the data flew EWR to SJU. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 365 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 UA 2143
For a booking, the cancellation rate is the figure to plan around on UA 2143: 3.84% of its 365 scheduled flights did not operate. A late arrival costs close to two hours, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- EWR to SJU, every carrier and departure
- SJU to EWR, the return direction
- United Airlines 1556 on the same route78.1%
- United Airlines 1543 on the same route64.2%
- Newark Liberty International (EWR) delay statistics
- Luis Munoz Marin International (SJU) delay statistics
- United Airlines on-time record
- Every United Airlines flight number with a record
- The most and least reliable flight numbers in the US
- What a cancellation rate actually tells you (and what it hides)
A flight number here means United Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
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.