Flight number record
DL 815
Delta Air Lines · Seattle to Nashville
- Route
- SEA → BNA
- Departs
- 17:35
- Flights
- 294
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 815, check with Delta Air Lines.
DL 815 lands a B+, 3 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 294 flights, with a median arrival 9 minutes early.
Key figures
On time
80.1%
Arrivals under 15 minutes late, of 292 completed flights
Avg delay
63 min
Across delayed arrivals only, not all flights
Cancelled
0.68%
National rate is 1.89%
1 hour+ late
8.2%
National rate is 8.3%
These figures cover 294 flights between September 2025 and August 2026. Beyond the headline rate, 8.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When DL 815 flies
DL 815 flies SEA to BNA without a single fixed slot. Its most common scheduled departure was 17:35, used on 108 of 294 flights, with 17:30 (88 flights) and 17:40 (57 flights) next.
- Departs 17:35108 flights36.7%
- Departs 17:3088 flights29.9%
- Departs 17:4057 flights19.4%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 17:35 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and DL 815 runs 12 points better at 80.1%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
DL 815 next to SEA to BNA
Every carrier on SEA to BNA combined arrived on time 80.6% of the time across 1,481 flights, so DL 815 is about level with it. Delta flew 516 flights on the same city pair under all its flight numbers, including this one, and those ran 83.0% on time. Across its whole network Delta Air Lines managed 81.1%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 815thin sample | 294 | 80.1% | 63 min | 0.68% | B+ |
| All Delta Air Lines on SEA–BNA | 516 | 83.0% | 61 min | 0.97% | B+ |
| All carriers on SEA–BNA | 1,481 | 80.6% | 48 min | 0.88% | B+ |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 815 quarter by quarter
DL 815 did not run the same all year. Its best quarter was Apr–Jun 2026 at 91.1% on time and its weakest Jul–Sep 2026 at 63.9%, a swing of 27 points on roughly 98 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202522 flights—
- Oct–Dec 202591 flights81.3%
- Jan–Mar 202628 flights—
- Apr–Jun 202691 flights91.1%
- Jul–Sep 202662 flights63.9%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, DL 815 did best on Thursday at 90.2% on time and worst on Friday at 70.7%. Each day rests on about 42 flights, so a gap of 20 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 815 runs when it is late
DL 815 often beats the schedule: 109 of 292 completed flights, 37%, arrived 15 minutes or more early. The 58 late arrivals split 17 under half an hour, 17 between 30 and 60 minutes, and 24 an hour or more.
- 15+ min early109 flights37.3%
- Within 15 min125 flights42.8%
- 15–29 min late17 flights5.8%
- 30–59 min late17 flights5.8%
- 1–2 hours late18 flights6.2%
- 2+ hours late6 flights2.1%
Scale runs 0% to 100%.
Share of 292 completed flights by arrival against schedule.
12 of 61 late departures made up the time and arrived on time, 20% of them. 9 flights left on time and still arrived late.
The worst days
Worst days for DL 815
The latest arrival of the period was on 27 December 2025, 3 hours 55 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on five of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 27 December 2025 | 3 hours 55 minutes | Carrier |
| 23 August 2026 | 3 hours 40 minutes | Carrier |
| 22 July 2026 | 3 hours 32 minutes | Carrier |
| 14 June 2026 | 2 hours 47 minutes | Carrier |
| 15 July 2026 | 2 hours 27 minutes | Carrier |
Delay causes
Why DL 815 runs late
Carrier accounts for 53% of the 3,645 delay minutes carriers reported here, and the remaining four split what is left.
- 53%Carrier
- 31%Late-arriving aircraft
- 13%National Airspace System
- 3%Extreme weather
The largest share of delay minutes, 53%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,929 of the 3,645 delay minutes reported here. The split is drawn from 3,645 delay minutes reported on DL 815.
Cancellations are rare at 0.68%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and routes
What a delay on this flight costs
8.2% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.
At 1,978 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The same number turns up on one other city pair in the data, including ATL to CHA (35), but none flew often enough under DL 815 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SEA to BNA only.
One caution: this is a thin sample. 294 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.
What to do with this
Booking DL 815
For a booking, read DL 815 as 80.1% on time with 0.68% cancelled over 294 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- SEA to BNA, every carrier and departure
- BNA to SEA, the return direction
- Alaska Airlines 382 on the same route81.9%
- Alaska Airlines 522 on the same route83.7%
- Seattle-Tacoma International (SEA) delay statistics
- Nashville International (BNA) delay statistics
- Delta Air Lines on-time record
- Every Delta Air Lines flight number with a record
- The most and least reliable flight numbers in the US
- Worst months to fly in the US, ranked by the data
A flight number here means Delta Air Lines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.