Flight number record
UA 2143
United Airlines · Newark to San Juan
- Route
- EWR → SJU
- Departs
- 08:00
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s UA 2143, check with United Airlines.
UA 2143 draws a C−. About one flight in three arrives at least 15 minutes late, and the typical late arrival is close to two hours behind schedule. Build slack into anything you connect to. That rests on 365 flights, with a median arrival 4 minutes early.
The national on-time rate over the same period is 77.3%, so UA 2143 runs 10 points behind the country as a whole. Across a thousand flights that is about 102 extra late arrivals.
Key figures
On time
67.1%
Arrivals under 15 minutes late, of 353 completed flights
Avg delay
111 min
Across delayed arrivals only, not all flights
Cancelled
3.29%
National rate is 1.89%
1 hour+ late
14.4%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. Beyond the headline rate, 14.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Schedule
When UA 2143 flies
UA 2143 flies EWR to SJU without a single fixed slot. Its most common scheduled departure was 08:00, used on 212 of 365 flights, with 07:55 (143 flights) next.
- Departs 08:00212 flights58.1%
- Departs 07:55143 flights39.2%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 08:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and UA 2143 runs 17 points worse at 67.1%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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.
Against the route
UA 2143 next to EWR to SJU
Every carrier on EWR to SJU combined arrived on time 69.9% of the time across 2,078 flights, so UA 2143 is 3 points behind it. United flew 1,113 flights on the same city pair under all its flight numbers, including this one, and those ran 69.7% on time. Across its whole network United Airlines managed 78.8%, which this flight trails by 12 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| UA 2143 | 365 | 67.1% | 111 min | 3.29% | C− |
| All United Airlines on EWR–SJU | 1,113 | 69.7% | 80 min | 2.16% | C |
| All carriers on EWR–SJU | 2,078 | 69.9% | 81 min | 3.03% | C− |
| United Airlines, whole network | 830,825 | 78.8% | 73 min | 1.02% | 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 73 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 202530 flights73.3%
- Oct–Dec 202592 flights51.8%
- Jan–Mar 202690 flights73.3%
- Apr–Jun 202691 flights80.0%
- Jul–Sep 202662 flights58.1%
Scale runs 45% to 85%.
By weekday, UA 2143 did best on Wednesday at 74.5% on time and worst on Monday at 52.9%. Each day rests on about 52 flights, so a gap of 22 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late UA 2143 runs when it is late
UA 2143 often beats the schedule: 113 of 353 completed flights, 32%, arrived 15 minutes or more early. The 116 late arrivals split 27 under half an hour, 38 between 30 and 60 minutes, and 51 an hour or more.
- 15+ min early113 flights32.0%
- Within 15 min124 flights35.1%
- 15–29 min late27 flights7.6%
- 30–59 min late38 flights10.8%
- 1–2 hours late22 flights6.2%
- 2+ hours late29 flights8.2%
Scale runs 0% to 100%.
Share of 353 completed flights by arrival against schedule.
14 of 97 late departures made up the time and arrived on time, 14% of them. In the other direction, 33 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 SJU.
The worst days
Worst days for UA 2143
The latest arrival of the period was on 25 July 2026, 11 hours 36 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 |
|---|---|---|
| 25 July 2026 | 11 hours 36 minutes | Carrier |
| 16 March 2026 | 10 hours 55 minutes | Carrier |
| 21 February 2026 | 10 hours 49 minutes | Late-arriving aircraft |
| 24 March 2026 | 8 hours 33 minutes | Late-arriving aircraft |
| 10 September 2025 | 6 hours 44 minutes | Late-arriving aircraft |
Delay causes
Why UA 2143 runs late
Carrier accounts for 52% of the 13,000 delay minutes carriers reported here, and the remaining four split what is left.
- 52%Carrier
- 32%Late-arriving aircraft
- 14%National Airspace System
- 2%Extreme weather
The largest share of delay minutes, 52%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 6,716 of the 13,000 delay minutes reported here. The split is drawn from 12,849 delay minutes reported on UA 2143.
Cancellations run at 3.29%, against 1.89% nationally. That is about one flight in 30 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
14.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection 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: 3.29% 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 route76.9%
- 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
- Why the first flight of the morning is statistically safest
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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.