MDW to SJU flight delays & on-time performance
Nonstop flights from Chicago Midway International Airport to Luis Munoz Marin International Airport · 2,057 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at MDW or SJU right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Chicago (MDW) to San Juan (SJU) arrived on time 69% of the time in Aug 2025 – Jul 2026, worse than the 78% national average.
- 1.9% were cancelled, and 12% arrived an hour or more late.
- Southwest Airlines is the only airline reporting nonstop flights on this route.
- Departures scheduled around 7am did best (73% on time); around 8am did worst (68%).
- Sunday was the most reliable day to fly (86% on time) and Saturday the least (63%).
- The largest source of delay minutes was airline (crew, maintenance, cleaning, fueling) (39%).
Which airline is most on time from MDW to SJU?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| Southwest Airlines | 69% | 1.9% | 17 min | 11.5% | 53 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 7am73%15 flights
- 8am68%38 flights
Best day of the week
On-time arrival rate by day of departure.
- Saturday63%2.6% cancelled
- Sunday86%0.0% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Airline (crew, maintenance, cleaning, fueling)39%
- Air traffic control & airport congestion33%
- Late-arriving aircraft28%
- Extreme weather0%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Air traffic control & airport congestion100%
- Airline (crew, maintenance, cleaning, fueling)0%
- Extreme weather0%
- Security0%
MDW to SJU: common questions
- How often are MDW to SJU flights on time?
- 69% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Chicago to San Juan cancelled?
- 1.9% of scheduled flights were cancelled (1 of 53).
- How long are typical delays?
- Across all flights the average arrival delay was 17 min (early arrivals count as zero). Flights that were late arrived 48 min behind schedule on average, and 11.5% of flights were an hour or more late.
- How long is taxi time at MDW?
- Flights on this route spent 19 min taxiing from the gate to takeoff on average.
Related routes
Return trip: SJU to MDW — 67% on time
More flights from Chicago
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: MDW → SJU, nonstop flights by US airlines that report to the DOT. How we calculate this.