78% of flights from St. Louis to Pittsburgh arrived on time over the past 12 months. That is about the typical U.S. route. The 10 a.m. departures ran on time 87% of the time; the 7 p.m. ones 62%. 8% of flights arrived more than an hour late or not at all.
How late?
The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for STL → PIT: when a flight was late, it was under 45 minutes late 56% of the time. About 1 in 13 flights landed an hour or more late, and 1 in 104 three hours or more; 0.0% were cancelled outright.
- On time or early78%
- 15–30 min late8.4%
- 30–60 min late5.7%
- 1–2 hours late5.6%
- 2–3 hours late1.0%
- 3+ hours late1.0%
- Diverted0.2%
- Cancelled0.0%
Share of all 522 scheduled flights, past 12 months, by arrival time against schedule.
By airline
| Airline | Flights | On time | Cancelled | Typical arrival | 1h+ late | Avg when late | Operated by |
|---|---|---|---|---|---|---|---|
| Southwest Airlines | 522 | 78% | 0.0% | −5 min | 7.5% | +60 min | Southwest Airlines |
Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.
Best time of day to fly
On-time rate by scheduled departure hour (local time at STL). Delays build through the day as late planes knock on, so early flights usually do best.
Last flight of the day
On STL → PIT, each airline's last flight of the day was cancelled 0.0% of the time, against 0.0% for its earlier flights, about the same. It arrived 3+ hours late 1.8% of the time (earlier flights: 0.6%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.
| Airline | Last departure | Last: cancelled | Last: 3h+ late | Earlier: cancelled | Next morning |
|---|---|---|---|---|---|
| Southwest Airlines | 7:35 p.m. | 0.0% | 1.8% | 0.0% | first flight 10:25 a.m. |
Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.
By month
Each calendar month pooled over 2023–2026. Best: September (93%). Worst: May (64%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 79 | — | — |
| Tuesday | 77 | — | — |
| Wednesday | 77 | — | — |
| Thursday | 78 | — | — |
| Friday | 78 | — | — |
| Saturday | 47 | — | — |
| Sunday | 86 | — | — |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Month by month
Not enough months with data to draw a trend.
Questions
How often are flights from STL to PIT on time?
78% of 522 scheduled flights from St. Louis, MO to Pittsburgh, PA arrived within 15 minutes of schedule between September 2025 and August 2026. 0.0% were cancelled.
What is the best time of day to fly STL to PIT?
Flights scheduled to leave at 10 a.m. were the most reliable (87% on time). The 7 p.m. departures were the least (62%).
What month has the most delays from STL to PIT?
May (64% on time). The best month is September (93%), over 2023–2026.
Is the last flight of the day from STL to PIT more likely to be cancelled?
Not much. Each airline's last STL–PIT flight of the day was cancelled 0.0% of the time over the past year, against 0.0% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- PIT → STL (return)
- St. Louis Lambert (STL) delays by hour
- Flights into Pittsburgh (PIT)
- Southwest Airlines on-time record
- Connecting off this flight? Check the risk
Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.