Route profile
SJU→ORD
Flight reliability, delays and best times to fly from San Juan to Chicago, 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 53% of comparable major US routes (4,598 compared)
Calculated from 3,889 flights. How this is calculated
SJU → ORD arrives on time 78.0% of the time; the return trip, ORD → SJU, arrives on time 78.2% of the time.
SJU → ORD spends 35.9 minutes on the ground on a 2,072-mile trip: 16.7 minutes from pushback to wheels-up at SJU and 19.2 minutes from touchdown to gate at ORD.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
Every day of the week performs about the same on this route, steadier than 95% of 4,467 comparable routes.
80.6% on time on the best day (Sunday) against 76.4% on the worst (Thursday).
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 4,467 in the comparison.
Why SJU → ORD flights are cancelled
July 2023 – July 2026
SJU → ORD cancelled 50 of 3,889 scheduled flights — about 1 in every 78. The reason filed most often was the airline, 42.0% of the cancellations coded on this route — about 1 in every 185 scheduled flights.
Share of cancellations
Of 50 cancelled departures carrying a reason code.
What each reason means
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
21 cancellations, 42.0% of the total.
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
20 cancellations, 40.0% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
9 cancellations, 18.0% 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.
50 coded cancellations were recorded on SJU → ORD; the section appears from 50.
When it goes wrong
July 2023 – July 2026
37 min late
against a median of 7 min early
Percentiles over 3,889 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at ORD after arriving from SJU.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 38% | Likely to miss |
| 45 min | 21% | High risk |
| 60 min | 13% | Some risk |
| 90 min | 6.1% | Some risk |
| 120 min | 3.5% | 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 1.29% of the time and diverts 1.26% of the time, which a late arrival never shows up in.
Chance of missing is the share of 3,790 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 37 minutes late (90th-percentile gate arrival delay), over 3,889 operations.
Any other layover length: connection checker.
Best time to fly
SJU → ORD flights departing 5–9 AM arrived on time 92.8% of the time, against 70.2% for 3–6 PM departures, a gap of 22.6 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 88.5% on time from 366 flights
- 7 AM: 95.5% on time from 382 flights
- 8 AM: 96.0% on time from 253 flights
- 9 AM to 1 PM: too few flights to score
- 2 PM: 74.9% on time from 457 flights
- 3 PM: 68.9% on time from 1,301 flights
- 4 PM: 72.9% on time from 561 flights
- 5 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why SJU → ORD 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 → ORD. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on SJU → ORD, at 38.1%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 92.8% of the time and 3–6 PM departures 70.2%.
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 | 1,764 | 82.2% | 0.62% | -7 min | 3.4% |
| Spirit Airlines | 1,130 | 78.4% | 2.48% | -11 min | 7.5% |
| American Airlines | 953 | 70.6% | 0.94% | -2 min | 9.6% |
United Airlines flew 45.9% of the 3,847 flights listed. Spirit Airlines cancelled 2.48% of its flights here against 0.62% for United Airlines.
United Airlines arrived on time 11.6 percentage points more often than American 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
Sunday is historically the most reliable day and Thursday the least, a gap of 4.2 percentage points.
By month
- Jan: 76.0%
- Feb: 81.3%
- Mar: 73.0%
- Apr: 85.2%
- May: 80.8%
- Jun: 79.3%
- Jul: 75.8%
- Aug: 73.9%
- Sep: 72.3%
- Oct: 74.5%
- Nov: 80.8%
- Dec: 81.1%
September is historically the weakest month and April the strongest, a spread of 12.9 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 (101)
- January 2024: too few flights to score (101)
- February 2024: too few flights to score (92)
- March 2024: 64.4% from 134 flights
- April 2024: too few flights to score (106)
- May 2024: too few flights to score (94)
- June 2024: 66.9% from 121 flights
- July 2024: 66.9% 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 (54)
- November 2024: too few flights to score (94)
- December 2024: 82.7% from 134 flights
- January 2025: too few flights to score (113)
- February 2025: too few flights to score (92)
- March 2025: 77.9% from 151 flights
- April 2025: 84.9% from 128 flights
- May 2025: too few flights to score (116)
- June 2025: too few flights to score (116)
- July 2025: 85.6% from 126 flights
- August 2025: too few flights to score (115)
- September 2025: too few flights to score (51)
- October 2025: too few flights to score (73)
- November 2025: too few flights to score (100)
- December 2025: 79.5% from 129 flights
- January 2026: 77.1% from 154 flights
- February 2026: 83.3% from 139 flights
- March 2026: 75.6% from 177 flights
- April 2026: 85.5% from 138 flights
- May 2026: too few flights to score (105)
- June 2026: too few flights to score (90)
- July 2026: 75.4% from 123 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 78.6% against 80.4% in the 12 months before — declining by 1.8 percentage points.
Data and methodology
Calculated by FlyerIntel from 3,889 SJU → ORD 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