Route reliability record
EWR→SJU
Newark to San Juan
- Flights
- 2,078
- Period
- September 2025 to August 2026
- Distance
- 1,608 mi
- Carriers
- 4
This route sits in the middle of the pack with a C−. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.3%. The late ones land a little over an hour behind schedule. That rests on 2,078 EWR to SJU flights, of which JetBlue Airways flew 687 at 73.0% on time.
Best time to fly EWR to SJU: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 84.3% of the time and Wednesday flights 74.8%, against 69.9% for the route overall.
The national on-time rate over the same period is 77.3%, so this route runs 7 points behind the country as a whole. Across a thousand flights that is about 74 extra late arrivals.
Key figures
On time
69.9%
Arrivals under 15 minutes late, of 2,014 completed flights
Avg delay
81 min
Across delayed arrivals only, not all flights
Cancelled
3.03%
National rate is 1.89%
Best carrier
JetBlue
73.0% on time across 687 flights
These figures cover 2,078 flights between September 2025 and August 2026. Beyond the headline rate, 11.8% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on EWR to SJU
The two carriers here are closely matched: 3 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| JetBlue Airways | 687 | 73.0% | 81 min | 3.93% | C− |
| United Airlines | 1,113 | 69.7% | 80 min | 2.16% | C |
| Spirit Airlinesthin sample | 126 | 67.5% | 72 min | 4.76% | C− |
| Frontier Airlinesthin sample | 152 | 58.9% | 94 min | 3.95% | D− |
JetBlue Airways cancels 3.9% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Flight by flight
Flights on EWR to SJU
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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Best ways to make this trip
The most reliable ways to fly Newark to San Juan
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 2 of the top 4 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. JFK → SJUNew York to San Juan | Delta Air Lines | 75.7% | 77.4% | 2.26% | 11am–2pm, Fri | DL 1961 12:25 |
| 2. EWR → SJUNewark to San Juan | JetBlue Airways | 70.1% | 73.0% | 3.93% | 5am–8am, Wed | — |
| 3. EWR → SJUNewark to San Juan | United Airlines | 68.2% | 69.7% | 2.16% | 8am–11am, Tue | UA 1556 09:43 |
| 4. JFK → SJUNew York to San Juan | JetBlue Airways | 64.9% | 67.7% | 4.14% | 5am–8am, Tue | B6 1603 08:29 |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 23 points, against 3 points between the best and worst carrier.
- 5am–8am203 flights84.3%
- 8am–11am890 flights73.4%
- 11am–2pm254 flights64.2%
- 2pm–5pm58 flights72.7%
- 5pm–8pm396 flights63.7%
- 8pm–5am277 flights61.4%
Scale runs 55% to 90%.
The 8pm–5am window is where this operation falls apart: 61.4% on time, against 84.3% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 890 flights scheduled in it.
Explore
Filter EWR to SJU by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On EWR to SJU, the best departure window is 5am–8am at 84.3% on time and the worst is 8pm–5am at 61.4%, a wide gap of 22.9 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am84.3%
- 8–11am73.4%
- 11am–2pm64.2%
- 2–5pm72.7%
- 5–8pm63.7%
- 8pm–5am61.4%
best all US flightsScale 55% to 95%.
Across the year
When delays peak on this route
This route's year swings by 27 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.
May is the best month on the calendar at 86.6% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. January was the busiest month here, with 214 flights.
Across the week, Wednesday is the strongest day at 74.8% on time and Monday the weakest at 63.2%, a spread of 12 points.
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 49,000 reported delay minutes.
- 39%Carrier
- 34%Late-arriving aircraft
- 23%National Airspace System
- 4%Extreme weather
- 0%Security
34% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 49,000 reported delay minutes here, that single category outweighs weather by 9 to one. The split is drawn from 49,329 reported delay minutes.
The largest share of delay minutes, 39%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 19,000 of the 49,000 delay minutes reported here.
Cancellations run at 3.03%, against 1.89% nationally. That is roughly 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 stage length
What a delay here actually costs
11.8% 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.
The return leg is a different operation and performs like one: it runs 74.6% on time across 2,077 flights, 5 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 5 points of difference.
The sample behind these figures is 2,078 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in SJU after this flight
What to do with this
Booking this route
Put together: the delay figures matter less here than the 3.03% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 2,014 completed flights over 12 months sit behind that.
Common questions
EWR to SJU questions
How often is EWR to SJU delayed?
Roughly 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 30.1% of the 2,078 flights in this analysis, against 22.7% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on EWR to SJU?
JetBlue Airways leads at 73.0% on time across 687 flights. United Airlines is at the other end on 69.7%, a gap of 3 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on EWR to SJU?
The 5am–8am departure window is the strongest at 84.3% on time. The 8pm–5am window is the weakest at 61.4%, 23 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 November delays on EWR to SJU?
November is the weakest month at 59.3% on time, compared with 86.6% in May. Across the year that is 27 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
- SJU to EWR — the return legseparate record
- Newark Liberty International (EWR) delay statistics
- Luis Munoz Marin International (SJU) delay statistics
- JetBlue Airways on EWR to SJU73.0%
- United Airlines on EWR to SJU69.7%
- Spirit Airlines on EWR to SJU67.5%
- Frontier Airlines on EWR to SJU58.9%
- EWR to MCO, a related route77.9%
- MCO to SJU, a related route73.8%
- EWR to ATL, a related route76.9%
- JetBlue Airways on-time record73.0%
- United Airlines on-time record69.7%
- Spirit Airlines on-time record67.5%
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
Direction matters. EWR to SJU and SJU to EWR 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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.