Route profile
SJU→BWI
Flight reliability, delays and best times to fly from San Juan to Baltimore, 1,565 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 49% of comparable major US routes (4,598 compared)
Calculated from 4,087 flights. How this is calculated · What counts as on time
SJU → BWI arrives on time 78.0% of the time; the return trip, BWI → SJU, arrives on time 67.7% of the time, a 10.3-point gap between the two directions of the same city pair.
SJU → BWI spends 24.3 minutes on the ground on a 1,565-mile trip: 17.0 minutes from pushback to wheels-up at SJU and 7.3 minutes from touchdown to gate at BWI.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
This route has stayed remarkably steady year over year, a smaller swing than 95% of 5,368 comparable routes.
79.2% on time over the most recent 12 months (2025-08 to 2026-07), against 79.5% in the 12 months before (2024-08 to 2025-07), virtually unchanged.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 5,368 in the comparison.
What sets this route apart
Where SJU to BWI differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
SJU to BWI is at its best against routes of similar length for flights scheduled at 10 AM: 88.5% arrive on time, 8.4 points ahead of the 80.1% those routes manage at that hour. Against all other routes the gap is 5.8 points.
SJU to BWI struggles most at 5 AM: 89.2% of its flights scheduled then arrive on time, 3 points behind the 92.2% on routes of similar length at the same hour. Against all other routes the gap is 3 points.
June is kinder to SJU to BWI than to routes of similar length: 79.7% on time against 71.7%, 8 points better. Against all other routes the gap is 7 points.
In March, SJU to BWI runs 5.1 points below routes of similar length, 73.4% on time to 78.5%. Against all other routes the gap is 4.5 points.
Southwest Airlines does better on SJU to BWI than on its routes of similar length: 79.6% on time here, 75.5% there, 4.1 points apart. Against all other routes the gap is 2.2 points.
SJU to BWI against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 10 AM departures | 88.5% | routes of similar length | 80.1% | +8.4 pts | 192 here, 90,614 there |
| Hour: 5 AM departures | 89.2% | routes of similar length | 92.2% | −3.0 pts | 665 here, 43,547 there |
| Month: June | 79.7% | routes of similar length | 71.7% | +8.0 pts | 360 here, 140,227 there |
| Month: March | 73.4% | routes of similar length | 78.5% | −5.1 pts | 368 here, 132,207 there |
| Airline: Southwest Airlines | 79.6% | routes of similar length | 75.5% | +4.1 pts | 2,450 here, 347,742 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 1,565 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
Why SJU → BWI flights are cancelled
July 2023 – July 2026
SJU → BWI cancelled 60 of 4,087 scheduled flights — about 1 in every 68. The reason filed most often was extreme weather, 51.7% of the cancellations coded on this route — about 1 in every 132 scheduled flights.
Share of cancellations
Of 60 cancelled departures carrying a reason code.
What each reason means
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
31 cancellations, 51.7% of the total.
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
23 cancellations, 38.3% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
6 cancellations, 10.0% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
60 coded cancellations were recorded on SJU → BWI; the section appears from 50.
When it goes wrong
July 2023 – July 2026
38 min late
against a median of 3 min early
Percentiles over 4,087 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at BWI after arriving from SJU.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 42% | Likely to miss |
| 45 min | 21% | High risk |
| 60 min | 13% | Some risk |
| 90 min | 5.8% | Some risk |
| 120 min | 3.7% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.47% of the time and diverts 0.49% of the time, which a late arrival never shows up in.
Chance of missing is the share of 4,007 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 38 minutes late (90th-percentile gate arrival delay), over 4,087 operations.
Any other layover length: connection checker.
Best time to fly
SJU → BWI flights departing 5–9 AM arrived on time 88.5% of the time, against 60.5% for 6–9 PM departures, a gap of 28.0 percentage points.
By departure window
By departure hour
- 12 AM to 4 AM: too few flights to score
- 5 AM: 89.2% on time from 669 flights
- 6 AM: 89.8% on time from 618 flights
- 7 AM: 85.6% on time from 286 flights
- 8 AM to 9 AM: too few flights to score
- 10 AM: 88.5% on time from 194 flights
- 11 AM to 12 PM: too few flights to score
- 1 PM: 74.8% on time from 167 flights
- 2 PM: too few flights to score
- 3 PM: 74.2% on time from 332 flights
- 4 PM: 67.5% on time from 584 flights
- 5 PM: 66.8% on time from 509 flights
- 6 PM to 11 PM: too few flights to score
Why SJU → BWI runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for SJU → BWI. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on SJU → BWI, at 41.4%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 88.5% of the time and 6–9 PM departures 60.5%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Southwest Airlines | 2,471 | 79.6% | 0.49% | -3 min | 4.1% |
| Spirit Airlines | 1,067 | 79.6% | 2.62% | -6 min | 7.5% |
| Frontier Airlines | 549 | 67.4% | 3.64% | 1 min | 11.3% |
Southwest Airlines flew 60.5% of the 4,087 flights listed. Frontier Airlines cancelled 3.64% of its flights here against 0.49% for Southwest Airlines.
Spirit Airlines arrived on time 12.2 percentage points more often than Frontier Airlines on this route.
Weekly and seasonal patterns
By day of week
Wednesday is historically the most reliable day and Saturday the least, a gap of 5.5 percentage points.
By month
- Jan: 77.6%
- Feb: 79.1%
- Mar: 73.4%
- Apr: 79.4%
- May: 77.3%
- Jun: 79.7%
- Jul: 71.6%
- Aug: 71.6%
- Sep: 80.7%
- Oct: 85.7%
- Nov: 86.6%
- Dec: 83.4%
August is historically the weakest month and November the strongest, a spread of 15.0 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 67.3% from 164 flights
- August 2023: 72.6% from 159 flights
- September 2023: too few flights to score (89)
- October 2023: too few flights to score (95)
- November 2023: too few flights to score (106)
- December 2023: too few flights to score (115)
- January 2024: 74.6% from 138 flights
- February 2024: too few flights to score (108)
- March 2024: 73.0% from 128 flights
- April 2024: 88.1% from 137 flights
- May 2024: 72.3% from 122 flights
- June 2024: 73.3% from 123 flights
- July 2024: 66.9% from 124 flights
- August 2024: too few flights to score (106)
- September 2024: too few flights to score (64)
- October 2024: too few flights to score (54)
- November 2024: too few flights to score (97)
- December 2024: 90.1% from 131 flights
- January 2025: too few flights to score (100)
- February 2025: too few flights to score (90)
- March 2025: 80.6% from 142 flights
- April 2025: 79.7% from 143 flights
- May 2025: too few flights to score (114)
- June 2025: 78.6% from 134 flights
- July 2025: 71.0% from 142 flights
- August 2025: too few flights to score (104)
- September 2025: too few flights to score (70)
- October 2025: too few flights to score (61)
- November 2025: too few flights to score (75)
- December 2025: too few flights to score (113)
- January 2026: too few flights to score (109)
- February 2026: too few flights to score (91)
- March 2026: too few flights to score (109)
- April 2026: too few flights to score (111)
- May 2026: too few flights to score (90)
- June 2026: too few flights to score (109)
- July 2026: 83.1% from 120 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 79.2% against 79.5% in the 12 months before — broadly unchanged.
Data and methodology
Calculated by FlyerIntel from 4,087 SJU → BWI flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed