Flight Reliability
UA 4921 · United Airlines
Houston → LCH (IAH–LCH)89% of its flights flew this route. The rest (IAH–CRP) are included in these numbers.
- 82%
- Arrive within 15 minutes
- 4 min
- Average arrival delay
- 1.3%
- Cancelled
- 10 min early
- Median arrival delay
Based on 224 historical flights. Data through May 2026.
What the data says
The 12–3 PM departure wins.
UA 4921 departing between 12–3 PM arrived on time 83% of the time, versus 75% between 6–9 AM.
Friday is doing you no favors.
UA 4921 arrived on time 97% of the time on Tuesdays and just 69% on Fridays. That gap is worth planning around.
A bit ahead of the United Airlines network.
UA 4921 arrived on time 82% of the time, versus 79% across the United Airlines network.
Recent months have been rougher.
UA 4921 arrived on time 76% of the time over the last three months in the data, compared with 90% in the three months before that.
The breakdown
- Mon75%(32 flights)
- Tue97%(33 flights)
- Wed91%(32 flights)
- Thu78%(32 flights)
- Fri69%(32 flights)
- Sat84%(25 flights)
- Sun82%(34 flights)
- 6–9 AM75%(24 flights)
- 12–3 PM83%(196 flights)
Jun 70% → May 83% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 70% | 27 |
| July 2025 | 81% | 26 |
| August 2025 | 79% | 28 |
| September 2025 | 90% | 30 |
| October 2025 | 100% | 31 |
| November 2025 | 80% | 30 |
| December 2025 | 65% | 17 |
| May 2026 | 83% | 30 |
- Departures on time
- 84%
- Diverted
- 0.4%
- Flights flown
- 220
- Months covered
- 9
Same route, other flights
Keep nerding
Based on 224 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.