Route profile
ORD→SJU
Flight reliability, delays and best times to fly from Chicago to San Juan, 2,072 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 54% of comparable major US routes (4,598 compared)
Calculated from 3,898 flights. How this is calculated
ORD → SJU arrives on time 78.2% of the time; the return trip, SJU → ORD, arrives on time 78.0% of the time.
ORD → SJU spends 30.4 minutes on the ground on a 2,072-mile trip: 25.0 minutes from pushback to wheels-up at ORD and 5.5 minutes from touchdown to gate at SJU.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
When it goes wrong
July 2023 – July 2026
41 min late
against a median of 5 min early
Percentiles over 3,898 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SJU after arriving from ORD.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 40% | Likely to miss |
| 45 min | 21% | High risk |
| 60 min | 13% | Some risk |
| 90 min | 6.5% | Some risk |
| 120 min | 3.8% | 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 1.05% of the time and diverts 0.33% of the time, which a late arrival never shows up in.
Chance of missing is the share of 3,844 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 41 minutes late (90th-percentile gate arrival delay), over 3,898 operations.
Any other layover length: connection checker.
Best time to fly
ORD → SJU flights departing 5–9 AM arrived on time 81.0% of the time, against 61.7% for 6–9 PM departures, a gap of 19.3 percentage points.
By departure window
By departure hour
- 12 AM to 6 AM: too few flights to score
- 7 AM: 83.3% on time from 270 flights
- 8 AM: 80.7% on time from 1,715 flights
- 9 AM: 77.6% on time from 381 flights
- 10 AM: too few flights to score
- 11 AM: 77.5% on time from 122 flights
- 12 PM: 68.7% on time from 187 flights
- 1 PM: too few flights to score
- 2 PM: 83.1% on time from 447 flights
- 3 PM to 5 PM: too few flights to score
- 6 PM: 63.4% on time from 269 flights
- 7 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why ORD → SJU runs late
July 2023 – July 2026
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
the inbound aircraft was late, so this flight started late
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 ORD → SJU. Only delays of 15 minutes or more are attributed.
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 |
|---|---|---|---|---|---|
| United Airlines | 1,765 | 80.3% | 0.23% | -4 min | 4.6% |
| Spirit Airlines | 1,136 | 75.8% | 2.38% | -6 min | 8.7% |
| American Airlines | 956 | 77.8% | 0.73% | -6 min | 7.8% |
United Airlines flew 45.8% of the 3,857 flights listed. Spirit Airlines cancelled 2.38% of its flights here against 0.23% for United Airlines.
United Airlines arrived on time 4.5 percentage points more often than Spirit Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Sunday the least, a gap of 7.1 percentage points.
By month
- Jan: 73.4%
- Feb: 88.9%
- Mar: 69.5%
- Apr: 85.4%
- May: 84.3%
- Jun: 76.2%
- Jul: 71.6%
- Aug: 70.7%
- Sep: 83.2%
- Oct: 86.8%
- Nov: 80.9%
- Dec: 79.3%
March is historically the weakest month and February the strongest, a spread of 19.4 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: too few flights to score (98)
- August 2023: too few flights to score (78)
- September 2023: too few flights to score (49)
- October 2023: too few flights to score (60)
- November 2023: too few flights to score (64)
- December 2023: too few flights to score (102)
- January 2024: too few flights to score (100)
- February 2024: too few flights to score (92)
- March 2024: 73.9% from 134 flights
- April 2024: too few flights to score (107)
- May 2024: too few flights to score (94)
- June 2024: 75.0% from 121 flights
- July 2024: 72.7% from 128 flights
- August 2024: too few flights to score (95)
- September 2024: too few flights to score (50)
- October 2024: too few flights to score (55)
- November 2024: too few flights to score (94)
- December 2024: 79.1% from 134 flights
- January 2025: too few flights to score (114)
- February 2025: too few flights to score (92)
- March 2025: 76.8% from 151 flights
- April 2025: 88.2% from 128 flights
- May 2025: too few flights to score (116)
- June 2025: too few flights to score (117)
- July 2025: 71.7% from 127 flights
- August 2025: too few flights to score (111)
- September 2025: too few flights to score (51)
- October 2025: too few flights to score (74)
- November 2025: too few flights to score (100)
- December 2025: 73.3% from 131 flights
- January 2026: 70.0% from 155 flights
- February 2026: 87.1% from 139 flights
- March 2026: 59.4% from 179 flights
- April 2026: 77.9% from 140 flights
- May 2026: too few flights to score (105)
- June 2026: too few flights to score (91)
- July 2026: 71.2% from 122 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 73.6% against 80.3% in the 12 months before — declining by 6.7 percentage points.
Data and methodology
Calculated by FlyerIntel from 3,898 ORD → SJU 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