Boston (BOS) to Louisville (SDF): On-Time Performance
Data through July 2026
The calendar drives reliability on BOS–SDF. September 2024 flights landed on schedule 98% of the time, but February 2025 dropped to 71% — a gap of 27 points. Across the full period the route averages 87% on-time against a national 78%.
- On-time
- 87%
- arrived <15 min late
- Avg delay
- 8 min
- completed flights
- Cancelled
- 1.0%
- Flights/day
- 1.9
- last 12 months
- Duration
- 2h 43m
- scheduled
- Distance
- 829 mi
Best airline from BOS to SDF
2 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Envoy Airmost reliable | 88% | 10 min | 0.9% | 227 |
| Republic Airways | 87% | 7 min | 1.0% | 1,217 |
Monthly on-time trend
Best time to fly from BOS to SDF
Aim for departures around 9 a.m. (90% on-time); avoid 12 p.m. departures (83%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Mondaybest | 90% | 8 min |
| Tuesday | 88% | 8 min |
| Wednesday | 90% | 6 min |
| Thursday | 85% | 7 min |
| Friday | 85% | 8 min |
| Saturday | 87% | 7 min |
| Sunday | 86% | 10 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft39%
- Airline operations40%
- National airspace system19%
- Weather1%
Frequently asked questions
- How often are flights from BOS to SDF delayed?
- 13% of BOS–SDF 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 8 minutes.
- Which airline is most reliable from BOS to SDF?
- Envoy Air has the best on-time record on this route at 88%, based on 227 flights. 2 airlines flew BOS–SDF frequently enough to compare in this period.
- What is the best time of day to fly from BOS to SDF?
- Departures around 9 a.m. have the best record (90% on-time), while departures around 12 p.m. have the worst (83%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from BOS to SDF?
- The scheduled BOS–SDF flight time averages 2h 43m over 829 miles. Actual arrival times vary — flights on this route land 15+ minutes late 13% of the time.
- How often are BOS to SDF flights cancelled?
- 1% 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 SDF?
- February 2025 was the roughest month in this dataset, with only 71% of arrivals on time. The best was September 2024 at 98%. If your dates are flexible, that 27-point gap is worth planning around.
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Based on 1,448 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.