Route reliability record
BNA→IAD
Nashville to Washington
- Flights
- 1,011
- Period
- July 2025 to June 2026
- Distance
- 542 mi
- Carriers
- 4
This route lands a B, level with the national rate of 77.6%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 1,011 BNA to IAD flights, with a median arrival 4 minutes early.
Best time to fly BNA to IAD: a 8am–11am departure, ideally on a Wednesday. Flights in that window arrived on time 87.5% of the time and Wednesday flights 83.7%, against 78.1% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.1%
Arrivals under 15 minutes late, of 996 completed flights
Avg delay
83 min
Across delayed arrivals only, not all flights
Cancelled
1.19%
National rate is 1.81%
Best carrier
United
77.8% on time across 935 flights
These figures cover 1,011 flights between July 2025 and June 2026. Beyond the headline rate, 8.5% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on BNA to IAD
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Southwest Airlinesthin sample | 1 | 100.0% | — | 0.00% | A+ |
| Republic Airwaysthin sample | 37 | 83.8% | 78 min | 0.00% | B+ |
| Allegiant Airthin sample | 38 | 78.9% | 82 min | 0.00% | B+ |
| United Airlines | 935 | 77.8% | 83 min | 1.28% | B |
Flight by flight
Flights on BNA to IAD
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
Best ways to make this trip
The most reliable ways to fly Nashville to Washington
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 4 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. BNA → IADNashville to Washington | United Airlines | 76.8% | 77.8% | 1.28% | 8am–11am, Wed (route) | UA 1709 08:30 |
| 2. BNA → BWINashville to Baltimore | Southwest Airlines | 76.8% | 78.4% | 2.05% | 8am–11am, Wed (route) | — |
| 3. BNA → DCANashville to Washington | Republic Airways | 72.9% | 75.1% | 2.90% | 8am–11am, Sat | YX 5708 06:05 |
| 4. BNA → DCANashville to Washington | Southwest Airlines | 71.2% | 72.2% | 1.45% | 8am–11am, Sat | — |
| 5. BNA → DCANashville to Washington | PSA Airlines | 58.5% | 65.1% | 10.08% | 5am–8am, Sat | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 19 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am4 flights—
- 8am–11am336 flights87.5%
- 11am–2pm371 flights77.6%
- 2pm–5pm—
- 5pm–8pm300 flights68.5%
- 8pm–5am—
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 87.5% of the time, against 68.5% for the evening window. That is 19 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 371 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 22 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
July is the worst month at 66.7% on time, 22 points below August, the best at 89.0%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 101 flights.
Across the week, Wednesday is the strongest day at 83.7% on time and Monday the weakest at 70.1%. 14 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Carrier accounts for 44% of the 18,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 44%Carrier
- 40%Late-arriving aircraft
- 12%National Airspace System
- 4%Extreme weather
40% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 18,000 reported delay minutes here, that single category outweighs weather by 11 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 18,031 reported delay minutes.
The largest share of delay minutes, 44%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 7,869 of the 18,000 delay minutes reported here.
Cancellations sit at 1.19% against a national 1.81%, which is ordinary. Diversions add another 0.30%.
Connections and stage length
What a delay here actually costs
8.5% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last an hour and a half, which a normal layover absorbs.
The 542 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 82.9% on time across 1,012 flights, 5 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 5 points of difference.
One caution: this is a thin sample. 1,011 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
Work out the risk of missing a connection in IAD after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 1,011 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 78.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 996 completed flights over 12 months sit behind that.
Common questions
BNA to IAD questions
How often is BNA to IAD delayed?
Roughly one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 21.9% of the 1,011 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is BNA to IAD compared with the rest of the country?
78.1% of flights arrive on time here against a national 77.6%, a difference of half a point in its favour. That is worth a B on this site's grading scale.
What time of day has the fewest delays on BNA to IAD?
The 8am–11am departure window is the strongest at 87.5% on time. The 5pm–8pm window is the weakest at 68.5%, 19 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are July delays on BNA to IAD?
July is the weakest month at 66.7% on time, compared with 89.0% in August. Across the year that is 22 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- IAD to BNA — the return legseparate record
- Nashville International (BNA) delay statistics
- Washington Dulles International (IAD) delay statistics
- BNA to ORD, a related route70.4%
- ATL to IAD, a related route76.5%
- BNA to DCA, a related route73.3%
- Southwest Airlines on-time record100.0%
- Republic Airways on-time record83.8%
- Allegiant Air on-time record78.9%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. BNA to IAD and IAD to BNA are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.