Flight number record
DL 1315
Delta Air Lines · Houston to Atlanta
- Route
- IAH → ATL
- Departs
- 07:00
- Flights
- 365
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1315, check with Delta Air Lines.
DL 1315 earns an A. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 11 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 365 flights, with a median arrival 10 minutes early.
Set against the rest of the country, DL 1315's record is 11 points better than the US average of 77.6%. That gap is worth roughly 109 fewer late arrivals for every thousand flights.
Key figures
On time
88.5%
Arrivals under 15 minutes late, of 358 completed flights
Avg delay
78 min
Across delayed arrivals only, not all flights
Cancelled
1.92%
National rate is 1.81%
1 hour+ late
5.3%
National rate is 8.1%
These figures cover 365 flights between July 2025 and June 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.
Schedule
When DL 1315 flies
DL 1315 flies IAH to ATL without a single fixed slot. Its most common scheduled departure was 07:00, used on 163 of 365 flights, with 07:05 (82 flights) and 07:01 (41 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 07:00163 flights44.7%
- Departs 07:0582 flights22.5%
- Departs 07:0141 flights11.2%
Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 07:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and DL 1315 runs level with that at 88.5%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
Against the route
DL 1315 next to IAH to ATL
Every carrier on IAH to ATL combined arrived on time 77.5% of the time across 4,906 flights, so DL 1315 is 11 points ahead of it. Delta flew 2,507 flights on the same city pair under all its flight numbers, including this one, and those ran 80.2% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 7 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1315 | 365 | 88.5% | 78 min | 1.92% | A |
| All Delta Air Lines on IAH–ATL | 2,507 | 80.2% | 66 min | 2.07% | B |
| All carriers on IAH–ATL | 4,906 | 77.5% | 67 min | 1.92% | B |
| Delta Air Lines, whole network | 1,038,570 | 81.6% | 71 min | 1.62% | B |
Across the year
DL 1315 quarter by quarter
DL 1315 did not run the same all year. Its best quarter was Jul–Sep 2025 at 94.5% on time and its weakest Jan–Mar 2026 at 80.2%, a swing of 14 points on roughly 91 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 202592 flights94.5%
- Oct–Dec 202592 flights87.8%
- Jan–Mar 202690 flights80.2%
- Apr–Jun 202691 flights91.2%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, DL 1315 did best on Wednesday at 94.2% on time and worst on Sunday at 77.1%. Each day rests on about 52 flights, so a gap of 17 points is worth noticing but could still narrow in another year.
Delay causes
Why DL 1315 runs late
One category carries most of the weight here. Carrier accounts for 75% of the 3,192 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.
- 75%Carrier
- 24%National Airspace System
- 1%Extreme weather
The largest share of delay minutes, 75%, 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 2,381 of the 3,192 delay minutes reported here. The split is drawn from 3,192 delay minutes reported on DL 1315.
Cancellations sit at 1.92% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
5.3% 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 a little over an hour, which a normal layover absorbs.
The 689 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.
Every one of the 365 flights under DL 1315 in the data flew IAH to ATL. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 365 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 1315
For a booking, read DL 1315 as 88.5% on time with 1.92% cancelled over 365 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- IAH to ATL, every carrier and departure
- ATL to IAH, the return direction
- Frontier Airlines 1404 on the same route66.9%
- Delta Air Lines 1069 on the same route91.0%
- Delta Air Lines 1682 on the same route76.6%
- Delta Air Lines 1585 on the same route77.8%
- Delta Air Lines 1572 on the same route78.9%
- Frontier Airlines 2400 on the same route53.3%
- George Bush Intercontinental (IAH) delay statistics
- 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.