83% of flights from Greer to Washington arrived on time over the past 12 months. That is better than the typical U.S. route. The 10 a.m. departures ran on time 90% of the time; the 7 p.m. ones 77%. 11% 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 → IAD: when a flight was late, it was under 45 minutes late 37% of the time. About 1 in 12 flights landed an hour or more late, and 1 in 50 three hours or more; 1.8% were cancelled outright.
- On time or early83%
- 15–30 min late3.7%
- 30–60 min late3.0%
- 1–2 hours late4.7%
- 2–3 hours late2.0%
- 3+ hours late2.0%
- Diverted0.2%
- Cancelled1.8%
Share of all 856 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 | 856 | 83% | 1.8% | −10 min | 8.6% | +112 min | CommutAir 89%, GoJet 10%, Mesa Airlines 1%, Republic Airways 0% |
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 → IAD, each airline's last flight of the day was cancelled 2.6% of the time, against 1.0% for its earlier flights (2.6× as often). It arrived 3+ hours late 2.9% of the time (earlier flights: 1.2%). 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 | 7:40 p.m. | 2.6% | 2.9% | 1.0% | first flight 10:30 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.
If you need to be in IAD tonight, book an earlier flight so there's a backup if it's cancelled.
By month
Each calendar month pooled over 2023–2026. Best: October (90%). Worst: January (68%).
By day of week
| Day | Flights | On time | Cancelled |
|---|---|---|---|
| Monday | 133 | 80% | 1.5% |
| Tuesday | 126 | 87% | 2.4% |
| Wednesday | 126 | 85% | 1.6% |
| Thursday | 129 | 87% | 1.6% |
| Friday | 129 | 81% | 0.8% |
| Saturday | 93 | — | — |
| Sunday | 120 | 75% | 3.3% |
Why flights were late
Share of delay minutes on flights 15+ minutes late, as reported to BTS by the airlines.
Cancellations: weather 13 · air traffic/airport 2
Month by month
Flight numbers on this route
Regular flights with at least 120 scheduled trips in the past year. Sorted by departure time.
| Flight | Departs | Flights | On time | Cancelled | Typical arrival | Operated by |
|---|---|---|---|---|---|---|
| UA 4958 | 10:00 a.m. | 305 | 90% | 1.3% | −14 min | CommutAir |
| UA 4959 | 2:55 p.m. | 286 | 78% | 2.1% | −7 min | CommutAir |
Worst days in the past year
| Date | Flights | On time | Cancelled |
|---|---|---|---|
| Aug 2, 2026 | 3 | 0% | 0 |
| Aug 28, 2026 | 3 | 0% | 0 |
| May 20, 2026 | 3 | 0% | 1 |
| Aug 10, 2026 | 3 | 33% | 0 |
| Jul 19, 2026 | 3 | 33% | 0 |
Nearby airport alternatives
Other ways to make the same trip, using airports within 60 miles of Greer or Washington. GSP → BWI has been 5 points more reliable.
| Route | Flights | On time | Cancelled |
|---|---|---|---|
| GSP → IAD (this route) | 856 | 83% | 1.8% |
| GSP → BWI Greenville-Spartanburg to Baltimore/Washington | 719 | 88% | 1.7% |
| GSP → DCA Greenville-Spartanburg to Washington Reagan National | 999 | 61% | 5.5% |
| AVL → DCA Asheville to Washington Reagan National | 518 | 55% | 7.3% |
Questions
How often are flights from GSP to IAD on time?
83% of 856 scheduled flights from Greer, SC to Washington, DC arrived within 15 minutes of schedule between September 2025 and August 2026. 1.8% were cancelled.
What is the best time of day to fly GSP to IAD?
Flights scheduled to leave at 10 a.m. were the most reliable (90% on time). The 7 p.m. departures were the least (77%).
What month has the most delays from GSP to IAD?
January (68% on time). The best month is October (90%), over 2023–2026.
Is the last flight of the day from GSP to IAD more likely to be cancelled?
Yes. Each airline's last GSP–IAD flight of the day was cancelled 2.6% of the time over the past year, against 1.0% for its earlier flights. If the last flight is cancelled, the next one is usually the following morning.
Related
- IAD → GSP (return)
- Greenville-Spartanburg (GSP) delays by hour
- Flights into Washington Dulles (IAD)
- 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.