Louisville (SDF) to Boston (BOS): On-Time Performance
Data through July 2026
The calendar drives reliability on SDF–BOS. January 2026 flights landed on schedule 87% of the time, but September 2025 dropped to 36% — a gap of 51 points. Across the full period the route averages 72% on-time against a national 78%. Morning departures also hold up better than evening ones (91% vs 66%), which matters most in the rough months.
- On-time
- 72%
- arrived <15 min late
- Avg delay
- 19 min
- completed flights
- Cancelled
- 1.5%
- Flights/day
- 1.9
- last 12 months
- Duration
- 2h 27m
- scheduled
- Distance
- 829 mi
Best airline from SDF to BOS
2 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Republic Airwaysmost reliable | 75% | 18 min | 1.6% | 1,217 |
| Envoy Air | 60% | 24 min | 0.9% | 227 |
Monthly on-time trend
Best time to fly from SDF to BOS
Aim for departures around 10 a.m. (91% on-time); avoid 3 p.m. departures (58%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 73% | 20 min |
| Tuesday | 73% | 21 min |
| Wednesday | 72% | 18 min |
| Thursday | 69% | 22 min |
| Friday | 71% | 18 min |
| Saturdaybest | 82% | 15 min |
| Sunday | 68% | 21 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft20%
- Airline operations13%
- National airspace system55%
- Weather11%
Frequently asked questions
- How often are flights from SDF to BOS delayed?
- 28% of SDF–BOS 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 19 minutes.
- Which airline is most reliable from SDF to BOS?
- Republic Airways has the best on-time record on this route at 75%, based on 1,217 flights. 2 airlines flew SDF–BOS frequently enough to compare in this period.
- What is the best time of day to fly from SDF to BOS?
- Departures around 10 a.m. have the best record (91% on-time), while departures around 3 p.m. have the worst (58%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from SDF to BOS?
- The scheduled SDF–BOS flight time averages 2h 27m over 829 miles. Actual arrival times vary — flights on this route land 15+ minutes late 28% of the time.
- How often are SDF to BOS 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 SDF to BOS?
- September 2025 was the roughest month in this dataset, with only 36% of arrivals on time. The best was January 2026 at 87%. If your dates are flexible, that 51-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.