77% of flights leaving Knoxville (TYS) arrived on time over the past 12 months, right at the national average of 76%. That ranks 37 of 76 large U.S. airports. About 63 flights leave TYS on a typical day; 2.0% were cancelled. 78% pushed back from the gate on time, so most of the lateness is already there when the flight leaves the gate.
At a glance
- Best hour to fly: 5 a.m. (90% on time). Worst: 8 p.m. (59%).
- Best month: October (84%). Worst: July (72%).
- Most reliable airline here: Delta Air Lines (81%), vs Allegiant Air at 72%.
- Biggest delay cause: late-arriving aircraft (41% of delay minutes).
- Year on year: getting worse (79% → 77%).
How late?
The on-time rate treats a flight 20 minutes late the same as one 5 hours late. Here's the split for flights leaving TYS: when a flight was late, it was under 45 minutes late 44% of the time. About 1 in 11 flights landed an hour or more late, and 1 in 38 three hours or more; 2.0% were cancelled outright.
- On time or early77%
- 15–30 min late5.9%
- 30–60 min late5.2%
- 1–2 hours late4.9%
- 2–3 hours late1.9%
- 3+ hours late2.6%
- Diverted0.4%
- Cancelled2.0%
Share of all 22,964 scheduled flights, past 12 months, by arrival time against schedule.
Best time of day to fly out of TYS
Time of day matters more at TYS than almost anything else you control. Flights scheduled to leave at 5 a.m. arrived on time 90% of the time; at 8 p.m. it was 59%, a 31-point gap. Taken together, early departures (5–9 a.m.) ran 84% on time against 64% for the evening bank (5–10 p.m.). Early planes usually start the day at the airport, so they haven't had a chance to pick up delays elsewhere. By evening a late inbound aircraft, a crew running out of duty hours or an afternoon thunderstorm can push one late flight into the next. Cancellations cluster too: 8 p.m. departures were cancelled 4.4% of the time, against 2.0% overall.
Hour × month
Combine the two and the spread is wider still. The most reliable combination at TYS was a 5 a.m. departure in October (96% on time); the least, 6 p.m. in July (49%). If you can only move one thing, move the hour. Departure hour usually shifts the odds more than the month does.
Each cell: on-time rate for that departure hour in that calendar month, 2023–2026. Find your travel month, then look along the row for the greenest hour.
Best and worst months
July is the hardest month at TYS, with 72% of flights on time across 2023–2026; October is the best at 84%. Summer (June–August) runs 9 points worse than autumn: heavy schedules, peak loads and afternoon thunderstorms. Winter costs 7 points against autumn. Cancellations peak in January (6.3% of flights).
Airlines at TYS
American Airlines runs 37% of departures from TYS. Among airlines with at least 1,000 departures here, Delta Air Lines was the most reliable (81% on time) and Allegiant Air the least (72%), a 9-point difference. On a route where both fly, that difference is worth more than a small fare gap.
| Airline | Departures | On time | Left on time | Cancelled | Typical arrival |
|---|---|---|---|---|---|
| American Airlines | 8,419 | 75% | 75% | 3.0% | −9 min |
| Delta Air Lines | 5,313 | 81% | 80% | 2.4% | −13 min |
| United Airlines | 4,749 | 80% | 83% | 1.5% | −11 min |
| Allegiant Air | 3,341 | 72% | 76% | 0.5% | −5 min |
| Southwest Airlines | 1,010 | 80% | 78% | 0.2% | −8 min |
| Frontier Airlines | 132 | 76% | 75% | 0.0% | −16 min |
Why flights are late at TYS
Airlines report a cause for every flight that arrives 15 or more minutes late. At TYS, 41% of delay minutes came from late-arriving aircraft: the plane showed up late from its previous flight, so the delay started somewhere else. Next is the airlines themselves at 36%. That's why the first flight of the morning is the safest bet: it has no earlier flight to inherit a delay from. Of the 469 cancellations, 64% were blamed on weather.
The average taxi from gate to takeoff is 18 minutes, about typical for a large U.S. airport.
Month by month
Over the latest 12 months 77% of TYS departures were on time, against 79% in the 12 months before, a decline of 2 points. The best recent month was September 2025 (85%); the worst, December 2025 (72%).
Worst cancellation days
The worst single day in the past year was Saturday, Jan 31, 2026, when 89% of 47 scheduled departures were cancelled. Days like that are usually a major storm, a system outage or a holiday peak hitting bad weather. No average predicts them, so on a stormy forecast, check your airline's travel waivers.
| Date | Departures | Cancelled | On time |
|---|---|---|---|
| Jan 31, 2026 | 47 | 89% | 0% |
| Jan 25, 2026 | 55 | 65% | 20% |
| Jan 26, 2026 | 59 | 39% | 17% |
| Jan 24, 2026 | 47 | 32% | 47% |
| Jan 27, 2026 | 45 | 29% | 42% |
| Mar 16, 2026 | 68 | 22% | 7% |
| Feb 1, 2026 | 55 | 18% | 36% |
| Feb 23, 2026 | 59 | 14% | 63% |
| Nov 9, 2025 | 67 | 13% | 46% |
| Jul 21, 2026 | 63 | 13% | 56% |
Last flights of the day
The last flight of the day is a different bet. Across routes from TYS, each airline's final departure was cancelled 3.2% of the time, against 2.0% for its earlier flights (1.6× as often). Late in the day crews run short on duty hours, aircraft arrive late from elsewhere, and with no later flight to fold passengers into, cancelling is easier for the airline. 3.2% of last flights landed 3+ hours late. The riskiest last flight out was American Airlines to Washington (8.1% cancelled).
| Last flight to | Airline | Leaves | Cancelled | 3h+ late | On time |
|---|---|---|---|---|---|
| DCA Washington | American Airlines | 6:53 p.m. | 8.1% | 7.3% | 53% |
| LGA New York | Delta Air Lines | 5:35 p.m. | 9.1% | 2.8% | 60% |
| ORD Chicago | American Airlines | 6:43 p.m. | 7.2% | 4.2% | 51% |
| ORD Chicago | United Airlines | 5:45 p.m. | 3.6% | 5.5% | 56% |
| FLL Fort Lauderdale | Allegiant Air | 5:02 p.m. | 0.8% | 6.8% | 28% |
| DFW Dallas | American Airlines | 8:11 p.m. | 4.7% | 2.8% | 60% |
| PHL Philadelphia | American Airlines | 6:36 p.m. | 3.3% | 2.8% | 72% |
| PIE St. Petersburg | Allegiant Air | 6:06 p.m. | 0.0% | 6.0% | 62% |
| DTW Detroit | Delta Air Lines | 5:23 p.m. | 1.5% | 3.8% | 74% |
| MSP Minneapolis | Delta Air Lines | 6:36 p.m. | 0.8% | 4.1% | 73% |
| CLT Charlotte | American Airlines | 7:59 p.m. | 2.7% | 1.6% | 71% |
| IAH Houston | United Airlines | 3:25 p.m. | 1.1% | 3.0% | 76% |
Each airline's last scheduled departure of the day on a route, on days it flies the route at least twice; past 12 months. Riskiest first.
Tips for flying out of TYS
- Book the earliest departure you can live with. At TYS the 5 a.m. flights do best.
- Traveling in July? Leave extra slack for anything that can't move: cruises, weddings, the last connection of the day.
- Choosing between airlines? Delta Air Lines has the better record here.
- Need to arrive tonight? Don't book the last flight out of TYS; the one before it leaves you a backup.
- Delayed already? Most delays at TYS come from late-arriving aircraft. If your inbound plane is late, your flight will be too, whatever the board says.
Routes from TYS
Where you're going matters too. From TYS, the most reliable busy route was to Washington (IAD, 84% on time) and the least reliable to Chicago (ORD, 67%). Flights into congested airports inherit their delays: an air traffic program at the destination holds planes on the ground here.
Least reliable first. Routes with at least 365 flights a year.
| To | Flights | On time | Cancelled | Typical arrival |
|---|---|---|---|---|
| FLL Fort Lauderdale | 478 | 51% | 0.8% | +12 min |
| DCA Washington | 1,021 | 66% | 4.4% | −3 min |
| ORD Chicago | 2,733 | 67% | 3.7% | −4 min |
| SFB Sanford | 635 | 68% | 0.6% | −2 min |
| LGA New York | 1,042 | 73% | 6.3% | −10 min |
| PIE St. Petersburg | 525 | 73% | 0.8% | −5 min |
| DFW Dallas | 1,761 | 75% | 3.3% | −9 min |
| PHL Philadelphia | 1,031 | 78% | 2.6% | −13 min |
| DTW Detroit | 942 | 78% | 1.0% | −11 min |
| CLT Charlotte | 2,778 | 81% | 1.9% | −12 min |
| IAH Houston | 1,305 | 82% | 1.1% | −14 min |
| MIA Miami | 506 | 83% | 0.6% | −8 min |
| ATL Atlanta | 2,906 | 84% | 1.7% | −15 min |
| DEN Denver | 1,029 | 84% | 0.5% | −13 min |
| IAD Washington | 1,353 | 84% | 1.3% | −15 min |
| MSP Minneapolis | 487 | 87% | 0.8% | −12 min |
Flights into TYS
Arriving rather than leaving? These are the routes into McGhee Tyson, least reliable first. The weakest is from Fort Lauderdale (59% on time).
| From | Flights | On time | Cancelled |
|---|---|---|---|
| FLL Fort Lauderdale | 478 | 59% | 0.8% |
| DCA Washington | 1,021 | 63% | 3.9% |
| SFB Sanford | 635 | 63% | 0.6% |
| ORD Chicago | 2,733 | 65% | 3.3% |
| MSP Minneapolis | 487 | 68% | 1.0% |
| LGA New York | 1,042 | 69% | 6.1% |
| DFW Dallas | 1,762 | 70% | 2.9% |
| DTW Detroit | 942 | 72% | 1.1% |
| PHL Philadelphia | 1,031 | 73% | 2.7% |
| PIE St. Petersburg | 525 | 74% | 0.8% |
| MIA Miami | 506 | 75% | 0.6% |
| CLT Charlotte | 2,778 | 76% | 1.9% |
| IAD Washington | 1,353 | 78% | 1.3% |
| ATL Atlanta | 2,905 | 78% | 1.7% |
| DEN Denver | 1,029 | 81% | 0.4% |
| IAH Houston | 1,304 | 83% | 1.3% |
Questions about TYS delays
What is the best time to fly out of TYS?
Flights scheduled at 5 a.m.: over the past year 90% of TYS departures at that hour arrived on time, against 59% at 8 p.m., the worst hour.
What month has the most flight delays at TYS?
July (72% on time). October is the best month (84%).
Which airline is most on time at TYS?
Delta Air Lines: 81% of its TYS departures arrived on time over the past year. Allegiant Air had the weakest record at 72%.
Why are flights delayed at TYS?
The biggest cause was late-arriving aircraft (41% of delay minutes): the plane showed up late from its previous flight, so the delay started somewhere else. Then the airlines themselves (36%).
How often are flights cancelled at TYS?
2.0% of scheduled departures over the past 12 months, peaking in January at 6.3%.
Hours are scheduled local departure times. "On time" means arriving less than 15 minutes late at the destination; cancelled and diverted flights count as not on time. Method.