IAD to TYS flight delays
Washington, VA (IAD) Knoxville, TN (TYS) · 420 miles
94 flights · January 2025 – August 2026 · US Bureau of Transportation Statistics
83.7%
Arrived on time
Within 15 minutes of schedule
1.06%
Cancelled
Share of scheduled flights
153 min
When late, late by
Average across delayed arrivals
25 min
Delay per flight
Averaged over every flight flown
What the record says about this route
The shape of the lateness matters here. Flights on this route are not late often, but when they are late they are late by about 153 minutes — long enough to lose a connection or an evening. The on-time percentage looks reassuring and understates the consequence of being on the wrong flight.
The two directions do not behave alike. TYS to IAD arrives on time 5.5 points more often than the outbound. Delay accumulates through the flying day, so whichever direction is scheduled later tends to carry the worse record — which is an argument for booking the morning departure if the choice exists.
Flights from Washington to Knoxville keep to schedule more reliably than most. On a route this punctual the day you fly matters more than the airline you pick.
Every airline on IAD to TYS
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| Allegiant Air | 94 | 83.7% | 1.06% | 153 min | — |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
TYS to IAD Knoxville back to Washington 89.25% on time —Other routes from Washington
Common questions
Are flights from Washington to Knoxville usually delayed?
83.7% of flights on the IAD to TYS route arrived within 15 minutes of schedule, so roughly 2 in every ten arrived late. That is better than the average route in this record.
How often are IAD to TYS flights cancelled?
1.06% of scheduled flights did not operate — about 11 in every thousand. That is in the normal range.
When IAD to TYS flights are late, how late are they?
About 153 minutes on average across the flights that arrived more than 15 minutes behind schedule.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on IAD to TYS during January 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →