Flight number record
DL 3155
Delta Air Lines · Gulfport to Atlanta
- Route
- GPT → ATL
- Departs
- 06:00
- Flights
- 255
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 3155, check with Delta Air Lines.
DL 3155 earns an A. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 16 points better than the national rate of 77.3%. When something does go wrong the average delay runs about 2.4 hours. That rests on 255 flights, with a median arrival 10 minutes early.
Set against the rest of the country, DL 3155's record is 16 points better than the US average of 77.3%. That gap is worth roughly 159 fewer late arrivals for every thousand flights.
Key figures
On time
93.2%
Arrivals under 15 minutes late, of 249 completed flights
Avg delay
141 min
Across delayed arrivals only, not all flights
Cancelled
1.96%
National rate is 1.89%
1 hour+ late
3.6%
National rate is 8.3%
These figures cover 255 flights between September 2025 and August 2026. The median arrival is 10 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Schedule
When DL 3155 flies
DL 3155 flies GPT to ATL without a single fixed slot. Its most common scheduled departure was 06:00, used on 100 of 255 flights, with 06:30 (86 flights) and 06:05 (38 flights) next.
- Departs 06:00100 flights39.2%
- Departs 06:3086 flights33.7%
- Departs 06:0538 flights14.9%
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 06:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 3155 runs 4 points better at 93.2%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
DL 3155 next to GPT to ATL
Every carrier on GPT to ATL combined arrived on time 86.7% of the time across 1,322 flights, so DL 3155 is 7 points ahead of it. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 12 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 3155thin sample | 255 | 93.2% | 141 min | 1.96% | A |
| All Delta Air Lines on GPT–ATL | 1,322 | 86.7% | 98 min | 1.59% | A |
| All carriers on GPT–ATL | 1,322 | 86.7% | 98 min | 1.59% | A |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 3155 quarter by quarter
Quarter by quarter DL 3155 held fairly steady: 91.9% in Jan–Mar 2026, 95.6% in Apr–Jun 2026 and 90.3% in Jul–Sep 2026. A spread of 5 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Oct–Dec 202512 flights—
- Jan–Mar 202690 flights91.9%
- Apr–Jun 202691 flights95.6%
- Jul–Sep 202662 flights90.3%
Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, DL 3155 ranged from 89.2% on Saturday to 97.2% on Tuesday. With about 36 flights behind each day, a spread of 8 points is inside normal variation, so the day you fly is not worth changing for this flight.
Arrival by arrival
How late DL 3155 runs when it is late
DL 3155 often beats the schedule: 79 of 249 completed flights, 32%, arrived 15 minutes or more early. When DL 3155 is late it tends to be very late: 9 of its 17 late arrivals were an hour or more behind, and 7 were two hours or more.
- 15+ min early79 flights31.7%
- Within 15 min153 flights61.4%
- 15–29 min late5 flights2.0%
- 30–59 min late3 flights1.2%
- 1–2 hours late2 flights0.8%
- 2+ hours late7 flights2.8%
Scale runs 0% to 100%.
Share of 249 completed flights by arrival against schedule.
Only 15 of 249 completed flights left 15 minutes late or more, too few to say how often the time is made up.
The worst days
Worst days for DL 3155
The latest arrival of the period was on 17 July 2026, 11 hours 9 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 17 July 2026 | 11 hours 9 minutes | Carrier |
| 26 July 2026 | 4 hours 28 minutes | Late-arriving aircraft |
| 9 March 2026 | 3 hours 58 minutes | Carrier |
| 19 August 2026 | 3 hours 55 minutes | Carrier |
| 30 May 2026 | 3 hours 48 minutes | Carrier |
Delay causes
Why DL 3155 runs late
Carrier accounts for 70% of the 2,402 delay minutes carriers reported here, and the remaining four split what is left.
- 70%Carrier
- 19%National Airspace System
- 11%Late-arriving aircraft
The largest share of delay minutes, 70%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,676 of the 2,402 delay minutes reported here. The split is drawn from 2,402 delay minutes reported on DL 3155.
Cancellations sit at 1.96% against a national 1.89%, which is ordinary. Diversions add another 0.39%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 3.6% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The same number turns up on one other city pair in the data, including AUS to DTW (110), but none flew often enough under DL 3155 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to GPT to ATL 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 3155
For a booking, read DL 3155 as 93.2% on time with 1.96% cancelled over 255 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- GPT to ATL, every carrier and departure
- ATL to GPT, the return direction
- Delta Air Lines 2718 on the same route84.7%
- Hartsfield-Jackson Atlanta International (ATL) 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.