87% of flights from Greer to Houston arrived on time over the past 12 months. That is better than the typical U.S. route. The 7 a.m. departures ran on time 91% of the time; the 5 p.m. ones 84%. 6% of flights arrived more than an hour late or not at all.
How late?
The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for GSP → IAH: when a flight was late, it was under 45 minutes late 43% of the time. About 1 in 22 flights landed an hour or more late, and 1 in 48 three hours or more; 1.2% were cancelled outright.
- On time or early87%
- 15–30 min late3.3%
- 30–60 min late3.9%
- 1–2 hours late1.8%
- 2–3 hours late0.7%
- 3+ hours late2.1%
- Diverted0.0%
- Cancelled1.2%
Share of all 673 scheduled flights, past 12 months, by arrival time against schedule.
By airline
| Airline | Flights | On time | Cancelled | Typical arrival | 1h+ late | Avg when late | Operated by |
|---|---|---|---|---|---|---|---|
| United Airlines | 673 | 87% | 1.2% | −17 min | 4.6% | +96 min | Mesa Airlines 96%, SkyWest 4% |
Airline = the name on the ticket. Regional flights (e.g. "Delta Connection") count under the ticketing airline, and the operator is listed.
Best time of day to fly
On-time rate by scheduled departure hour (local time at GSP). Delays build through the day as late planes knock on, so early flights usually do best.
Last flight of the day
On GSP → IAH, each airline's last flight of the day was cancelled 0.7% of the time, against 1.6% for its earlier flights, so here the last flight is actually the safer one. It arrived 3+ hours late 2.3% of the time (earlier flights: 2.3%). It matters more than the numbers suggest. Miss an earlier flight and there's another one that evening; miss the last one and you're usually waiting until morning.
| Airline | Last departure | Last: cancelled | Last: 3h+ late | Earlier: cancelled | Next morning |
|---|---|---|---|---|---|
| United Airlines | 5:10 p.m. | 0.7% | 2.3% | 1.6% | first flight 7:00 a.m. |
Last flight = the airline's last scheduled departure on this route that day, on days it flies the route at least twice; past 12 months. Times are typical scheduled times over the latest three months.
By month
Each calendar month pooled over 2023–2026. Best: February (91%). Worst: June (76%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 106 | 88% | 0.9% |
| Tuesday | 85 | — | — |
| Wednesday | 100 | 92% | 0.0% |
| Thursday | 103 | 90% | 0.0% |
| Friday | 104 | 85% | 1.0% |
| Saturday | 72 | — | — |
| Sunday | 103 | 87% | 3.9% |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: weather 8
Month by month
Not enough months with data to draw a trend.
Questions
How often are flights from GSP to IAH on time?
87% of 673 scheduled flights from Greer, SC to Houston, TX arrived within 15 minutes of schedule between September 2025 and August 2026. 1.2% were cancelled.
What is the best time of day to fly GSP to IAH?
Flights scheduled to leave at 7 a.m. were the most reliable (91% on time). The 5 p.m. departures were the least (84%).
What month has the most delays from GSP to IAH?
June (76% on time). The best month is February (91%), over 2023–2026.
Is the last flight of the day from GSP to IAH more likely to be cancelled?
No, the opposite. Each airline's last GSP–IAH flight of the day was cancelled 0.7% of the time over the past year, against 1.6% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- IAH → GSP (return)
- Greenville-Spartanburg (GSP) delays by hour
- Flights into Houston Bush Intercontinental (IAH)
- United Airlines on-time record
- Connecting off this flight? Check the risk
Domestic flights by the airlines that report to the U.S. DOT, plus their regional partners. "On time" means arriving less than 15 minutes after schedule; cancelled and diverted flights count as not on time. Past performance is a guide, not a forecast. Method.