Raleigh/Durham (RDU) to St. Louis (STL): On-Time Performance
Data through July 2026
The calendar drives reliability on RDU–STL. September 2025 flights landed on schedule 94% of the time, but July 2026 dropped to 62% — a gap of 32 points. Across the full period the route averages 83% on-time against a national 78%. Morning departures also hold up better than evening ones (94% vs 70%), which matters most in the rough months.
- On-time
- 83%
- arrived <15 min late
- Avg delay
- 10 min
- completed flights
- Cancelled
- 0.5%
- Flights/day
- 1.8
- last 12 months
- Duration
- 2h 11m
- scheduled
- Distance
- 668 mi
Monthly on-time trend
Best time to fly from RDU to STL
Aim for departures around 8 a.m. (97% on-time); avoid 7 p.m. departures (57%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 83% | 11 min |
| Tuesdaybest | 88% | 6 min |
| Wednesday | 85% | 8 min |
| Thursday | 76% | 13 min |
| Friday | 81% | 14 min |
| Saturday | 86% | 11 min |
| Sunday | 82% | 9 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft64%
- Airline operations25%
- National airspace system8%
- Weather3%
- Security1%
Frequently asked questions
- How often are flights from RDU to STL delayed?
- 17% of RDU–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 10 minutes.
- What is the best time of day to fly from RDU to STL?
- Departures around 8 a.m. have the best record (97% on-time), while departures around 7 p.m. have the worst (57%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from RDU to STL?
- The scheduled RDU–STL flight time averages 2h 11m over 668 miles. Actual arrival times vary — flights on this route land 15+ minutes late 17% of the time.
- How often are RDU to STL flights cancelled?
- 0.5% 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 RDU to STL?
- July 2026 was the roughest month in this dataset, with only 62% of arrivals on time. The best was September 2025 at 94%. If your dates are flexible, that 32-point gap is worth planning around.
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Based on 1,363 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.