Skip to content
DelayAtlas

Airport month record

SJUJAN

Luis Munoz Marin International in January 2026

Departures
3,306
Month
January 2026
National, same month
79.2%
Carriers
7
C−GRADE

Historical statistics for January 2026, not live status or a forecast for this year’s January. For today’s conditions at SJU, see live FAA status.

SJU in January carries a cancellation problem, not just a delay problem: 8.0% of scheduled flights never operate, against 4.7% nationally. Of the ones that do fly, close to three flights in four arrive on time, worth a C− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 3,306 flights, of which American Airlines flew 523 at 73.1% on time.

The national on-time rate over the same period is 79.2%, so sju in january runs 6 points behind the country as a whole. Across a thousand flights that is about 59 extra late arrivals.

Key figures

On time

73.3%

Arrivals under 15 minutes late, of 3,033 completed departures

Avg delay

91 min

Across delayed arrivals only, not all flights

Cancelled

7.96%

Nationally in January: 4.71%

Whole year

77.8%

SJU across all twelve months

These figures cover 3,306 departures from Luis Munoz Marin International in January 2026. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.

Against the year

January next to SJU's other months

Against SJU's own year, January ran 5 points worse than the twelve-month rate of 77.8%, which makes it number eleven of twelve months, best first. Cancellations are where January stands out: 7.96% of scheduled departures were called off, 4.3 times the airport's rate across the year. Either side of it, December ran 78.4% on time and February 74.7%, so a trip moved by a few weeks would have landed in a better stretch.

SJU month by month
MonthFlightsOn timeAvg delayCancelledGrade
July 20253,41575.4%80 min1.55%B
August 20252,97570.9%80 min0.77%C+
September 20251,96580.7%69 min0.00%B+
October 20252,18679.1%68 min0.46%B+
November 20252,71581.8%87 min1.07%B
December 20253,39378.4%79 min1.77%B
January 2026 (this page)3,30673.3%91 min7.96%C−
February 20262,83574.7%79 min3.17%C−
March 20263,44175.1%73 min2.06%B
April 20263,19078.4%68 min0.75%B+
May 20262,87584.7%64 min0.21%B+
June 20263,09583.1%76 min0.61%B+

Departure window

The best time of day to leave SJU in January

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 20 points, against 6 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am665 flights83.9%
  • 8am–11am348 flights83.2%
  • 11am–2pm342 flights79.2%
  • 2pm–5pm957 flights66.6%
  • 5pm–8pm674 flights68.6%
  • 8pm–5am320 flights63.8%

Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 63.8% on time, against 83.9% 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 2pm–5pm window is the busiest, with 957 flights scheduled in it.

Across the week, Wednesday is the strongest day at 79.8% on time and Monday the weakest at 60.6%. 19 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week60.6Mon78.1Tue79.8Wed75.3Thu78.3Fri78.6Sat61.3Sun
Monday: 60.6 percent on time. Tuesday: 78.1 percent on time. Wednesday: 79.8 percent on time. Thursday: 75.3 percent on time. Friday: 78.3 percent on time. Saturday: 78.6 percent on time. Sunday: 61.3 percent on time

Carrier by carrier

Which airlines ran best at SJU in January

The choice of carrier is not cosmetic here. American Airlines arrives on time 73.1% of the time; Frontier Airlines manages 67.1%. Sample sizes sit next to every figure, because a two-point gap across 503 flights means less than a ten-point one.

Carriers at SJU in January 2026
AirlineFlightsOn timeAvg delayCancelledGrade
JetBlue Airways97868.6%84 min8.18%C−
American Airlines52373.1%142 min9.75%C−
Frontier Airlines50367.1%93 min7.95%C−
Delta Air Linesthin sample36180.4%100 min6.37%B−
United Airlinesthin sample33181.5%56 min5.44%B−
Southwest Airlinesthin sample31882.2%41 min6.29%B−
Spirit Airlinesthin sample29271.5%82 min10.62%C−

American Airlines cancels 9.8% 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.

Route by route

Busiest routes out of SJU in January

Routes from SJU in January 2026
RouteFlightsOn timeAvg delayCancelledGrade
SJU to MCO · Orlando51077.2%85 min4.31%B−
SJU to JFK · New Yorkthin sample31073.7%97 min9.35%C−
SJU to MIA · Miamithin sample25072.5%115 min6.40%C−
SJU to EWR · Newarkthin sample21774.1%71 min9.22%C−
SJU to FLL · Fort Lauderdalethin sample21766.7%62 min6.91%C−
SJU to BOS · Bostonthin sample20763.6%108 min11.11%D−
SJU to ATL · Atlantathin sample19577.7%126 min4.62%B−
SJU to PHL · Philadelphiathin sample19459.0%111 min10.82%D−
SJU to ORD · Chicagothin sample15477.1%92 min8.44%B−
SJU to TPA · Tampathin sample13384.7%56 min6.77%B−
SJU to CLT · Charlottethin sample12180.4%204 min9.92%B−
SJU to BWI · Baltimorethin sample10980.8%85 min9.17%B−
SJU to DFW · Dallas-Fort Worththin sample10356.8%74 min14.56%D−
SJU to BDL · Hartfordthin sample8667.9%68 min9.30%C−
SJU to IAH · Houstonthin sample8188.3%42 min4.94%A−
SJU to IAD · Washingtonthin sample7489.9%100 min6.76%A−
SJU to RDU · Raleighthin sample4592.3%100 min13.33%A−
SJU to DTW · Detroitthin sample3667.6%36 min5.56%C−
SJU to MSP · Minneapolisthin sample3478.1%44 min5.88%B−
SJU to STT · Charlotte Amaliethin sample3160.0%82 min3.23%D−
SJU to DCA · Washingtonthin sample3144.4%99 min12.90%F−
SJU to STX · Christianstedthin sample3166.7%51 min3.23%C−
SJU to PVD · Providencethin sample3162.1%60 min6.45%D−
SJU to HPN · White Plainsthin sample3182.1%109 min6.45%B−
SJU to DEN · Denverthin sample3183.3%106 min3.23%B−

Delay causes

What held SJU up in January

One category carries most of the weight here. Carrier accounts for 44% of the 74,000 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.

  • Carrier
    44%
  • Late-arriving aircraft
    40%
  • National Airspace System
    11%
  • Extreme weather
    5%
  • Security
    0%

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 74,000 reported delay minutes here, that single category outweighs weather by 9 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 73,762 reported delay minutes.

Cancellations run at 7.96%, against 4.71% nationally. That is about one flight in twelve 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.

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.6% of arrivals land a full hour or more behind schedule, against 7.6% 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.

What to do with this

Flying from SJU in January

For a January trip through SJU: plan on this being one of the airport's harder months. The 5am–8am departures held up best at 83.9% on time, and with 10.6% of arrivals an hour or more late, a connection here deserves more slack than the same trip in May would.

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.