Boston (BOS) to St. Louis (STL): On-Time Performance
Data through July 2026
Boston (BOS) to St. Louis (STL) effectively runs on two schedules. In November 2024, 91% of arrivals were on time; in October 2025 that fell to 64% — a 26-point seasonal swing. Across the full period the route averages 78% on-time against a national 78%. Morning departures also hold up better than evening ones (91% vs 52%), which matters most in the rough months.
- On-time
- 78%
- arrived <15 min late
- Avg delay
- 14 min
- completed flights
- Cancelled
- 1.5%
- Flights/day
- 4.4
- last 12 months
- Duration
- 3h 7m
- scheduled
- Distance
- 1,047 mi
Best airline from BOS to STL
3 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Republic Airwaysmost reliable | 85% | 9 min | 3.8% | 468 |
| Envoy Air | 81% | 13 min | 1.4% | 918 |
| Southwest Airlines | 76% | 16 min | 1.0% | 1,957 |
Monthly on-time trend
Best time to fly from BOS to STL
Aim for departures around 5 a.m. (94% on-time); avoid 6 p.m. departures (46%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 74% | 16 min |
| Tuesday | 82% | 12 min |
| Wednesday | 82% | 13 min |
| Thursday | 76% | 15 min |
| Friday | 79% | 12 min |
| Saturdaybest | 82% | 10 min |
| Sunday | 74% | 18 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft58%
- Airline operations26%
- National airspace system13%
- Weather3%
Frequently asked questions
- How often are flights from BOS to STL delayed?
- 22% of BOS–STL flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 14 minutes.
- Which airline is most reliable from BOS to STL?
- Republic Airways has the best on-time record on this route at 85%, based on 468 flights. 3 airlines flew BOS–STL frequently enough to compare in this period.
- What is the best time of day to fly from BOS to STL?
- Departures around 5 a.m. have the best record (94% on-time), while departures around 6 p.m. have the worst (46%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from BOS to STL?
- The scheduled BOS–STL flight time averages 3h 7m over 1,047 miles. Actual arrival times vary — flights on this route land 15+ minutes late 22% of the time.
- How often are BOS to STL flights cancelled?
- 1.5% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from BOS to STL?
- October 2025 was the roughest month in this dataset, with only 64% of arrivals on time. The best was November 2024 at 91%. If your dates are flexible, that 26-point gap is worth planning around.
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Based on 3,343 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.