Flight number record
DL 3121
Delta Air Lines · Atlanta to Nashville
- Route
- ATL → BNA
- Departs
- 23:00
- Flights
- 255
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 3121, check with Delta Air Lines.
DL 3121 lands a B−, level with the national rate of 77.3%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 255 flights, with a median arrival 7 minutes early.
Key figures
On time
78.0%
Arrivals under 15 minutes late, of 245 completed flights
Avg delay
75 min
Across delayed arrivals only, not all flights
Cancelled
3.92%
National rate is 1.89%
1 hour+ late
8.2%
National rate is 8.3%
These figures cover 255 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 3121 flies
DL 3121 flies ATL to BNA without a single fixed slot. Its most common scheduled departure was 23:00, used on 80 of 255 flights, with 22:54 (58 flights) and 22:50 (44 flights) next.
- Departs 23:0080 flights31.4%
- Departs 22:5458 flights22.7%
- Departs 22:5044 flights17.3%
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 23:00 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and DL 3121 runs 8 points better at 78.0%. 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 3121 next to ATL to BNA
Every carrier on ATL to BNA combined arrived on time 79.6% of the time across 4,258 flights, so DL 3121 is 2 points behind it. Delta flew 3,369 flights on the same city pair under all its flight numbers, including this one, and those ran 80.6% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 3 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 3121thin sample | 255 | 78.0% | 75 min | 3.92% | B− |
| All Delta Air Lines on ATL–BNA | 3,369 | 80.6% | 56 min | 1.90% | B |
| All carriers on ATL–BNA | 4,258 | 79.6% | 59 min | 1.62% | B |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 3121 quarter by quarter
DL 3121 did not run the same all year. Its best quarter was Apr–Jun 2026 at 85.2% on time and its weakest Jul–Sep 2026 at 60.7%, a swing of 25 points on roughly 85 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.
- Oct–Dec 202512 flights—
- Jan–Mar 202690 flights82.1%
- Apr–Jun 202691 flights85.2%
- Jul–Sep 202662 flights60.7%
Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.
By weekday, DL 3121 did best on Wednesday at 94.4% on time and worst on Sunday at 65.7%. Each day rests on about 36 flights, so a gap of 29 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 3121 runs when it is late
The 54 late arrivals split 16 under half an hour, 18 between 30 and 60 minutes, and 20 an hour or more.
- 15+ min early47 flights19.2%
- Within 15 min144 flights58.8%
- 15–29 min late16 flights6.5%
- 30–59 min late18 flights7.3%
- 1–2 hours late13 flights5.3%
- 2+ hours late7 flights2.9%
Scale runs 0% to 100%.
Share of 245 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 51 departures that left 15 minutes late or more, only 6 made it up before arrival. 9 flights left on time and still arrived late.
The worst days
Worst days for DL 3121
The latest arrival of the period was on 30 June 2026, 7 hours 48 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). Three of the five worst days fell in March 2026.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 30 June 2026 | 7 hours 48 minutes | Carrier |
| 26 March 2026 | 7 hours 26 minutes | Carrier |
| 6 March 2026 | 4 hours 13 minutes | Extreme weather |
| 7 August 2026 | 3 hours | Carrier |
| 16 March 2026 | 2 hours 38 minutes | Late-arriving aircraft |
Delay causes
Why DL 3121 runs late
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 4,052 reported delay minutes.
- 41%Carrier
- 31%Late-arriving aircraft
- 14%Extreme weather
- 11%National Airspace System
- 2%Security
Extreme weather accounts for 14% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.4 times the usual weather exposure. The split is drawn from 4,052 delay minutes reported on DL 3121.
Cancellations run at 3.92%, against 1.89% nationally. That is about one flight in 25 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
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 a little over an hour, which a normal layover absorbs.
The same number turns up on four other city pairs in the data, including DTW to MSN (55), MSN to DTW (55) and XNA to ATL (1), but none flew often enough under DL 3121 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ATL to BNA only.
One caution: this is a thin sample. 255 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 3121
For a booking, the cancellation rate is the figure to plan around on DL 3121: 3.92% of its 255 scheduled flights did not operate. A late arrival costs a little over an hour, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- ATL to BNA, every carrier and departure
- BNA to ATL, the return direction
- Delta Air Lines 3069 on the same route92.7%
- Delta Air Lines 1490 on the same route71.9%
- Delta Air Lines 1693 on the same route76.9%
- Hartsfield-Jackson Atlanta International (ATL) 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
- What a cancellation rate actually tells you (and what it hides)
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.