Flight number record
DL 1284
Delta Air Lines · Atlanta to Houston
- Route
- ATL → IAH
- Departs
- 19:59
- Flights
- 356
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1284, check with Delta Air Lines.
DL 1284 sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.3%. The late ones land a little over an hour behind schedule. That rests on 356 flights, with a median arrival 1 minute early.
The national on-time rate over the same period is 77.3%, so DL 1284 runs 6 points behind the country as a whole. Across a thousand flights that is about 57 extra late arrivals.
Key figures
On time
71.6%
Arrivals under 15 minutes late, of 349 completed flights
Avg delay
69 min
Across delayed arrivals only, not all flights
Cancelled
1.97%
National rate is 1.89%
1 hour+ late
11.2%
National rate is 8.3%
These figures cover 356 flights between September 2025 and August 2026. Beyond the headline rate, 11.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When DL 1284 flies
DL 1284 flies ATL to IAH without a single fixed slot. Its most common scheduled departure was 19:59, used on 65 of 356 flights, with 20:10 (53 flights) next.
- Departs 19:5965 flights18.3%
- Departs 20:1053 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 19:59 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and DL 1284 runs 4 points better at 71.6%. 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 1284 next to ATL to IAH
Every carrier on ATL to IAH combined arrived on time 76.9% of the time across 4,965 flights, so DL 1284 is 5 points behind it. Delta flew 2,543 flights on the same city pair under all its flight numbers, including this one, and those ran 76.0% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1284thin sample | 356 | 71.6% | 69 min | 1.97% | C |
| All Delta Air Lines on ATL–IAH | 2,543 | 76.0% | 57 min | 1.97% | B |
| All carriers on ATL–IAH | 4,965 | 76.9% | 69 min | 1.79% | B |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 1284 quarter by quarter
DL 1284 did not run the same all year. Its best quarter was Jul–Sep 2025 at 80.0% on time and its weakest Jul–Sep 2026 at 52.5%, a swing of 28 points on roughly 71 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 202530 flights80.0%
- Oct–Dec 202591 flights74.4%
- Jan–Mar 202684 flights75.9%
- Apr–Jun 202689 flights75.3%
- Jul–Sep 202662 flights52.5%
Scale runs 45% to 85%.
By weekday, DL 1284 did best on Wednesday at 86.5% on time and worst on Sunday at 60.4%. Each day rests on about 51 flights, so a gap of 26 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 1284 runs when it is late
The 99 late arrivals split 27 under half an hour, 33 between 30 and 60 minutes, and 39 an hour or more.
- 15+ min early67 flights19.2%
- Within 15 min183 flights52.4%
- 15–29 min late27 flights7.7%
- 30–59 min late33 flights9.5%
- 1–2 hours late23 flights6.6%
- 2+ hours late16 flights4.6%
Scale runs 0% to 100%.
Share of 349 completed flights by arrival against schedule.
22 of 114 late departures made up the time and arrived on time, 19% of them. 7 flights left on time and still arrived late.
The worst days
Worst days for DL 1284
The latest arrival of the period was on 14 June 2026, 5 hours 28 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On three of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 14 June 2026 | 5 hours 28 minutes | Late-arriving aircraft |
| 6 August 2026 | 4 hours 23 minutes | Carrier |
| 18 June 2026 | 4 hours 18 minutes | Carrier |
| 8 November 2025 | 4 hours 11 minutes | Carrier |
| 11 July 2026 | 3 hours 25 minutes | Late-arriving aircraft |
Delay causes
Why DL 1284 runs late
Carrier accounts for 57% of the 6,838 delay minutes carriers reported here, and the remaining four split what is left.
- 57%Carrier
- 28%Late-arriving aircraft
- 12%National Airspace System
- 3%Extreme weather
The largest share of delay minutes, 57%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 3,917 of the 6,838 delay minutes reported here. The split is drawn from 6,838 delay minutes reported on DL 1284.
Cancellations sit at 1.97% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
11.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
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.
Every one of the 356 flights under DL 1284 in the data flew ATL to IAH. 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. 356 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 1284
For a booking, DL 1284 is one of the weaker ways to fly ATL to IAH: 5 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.
Related
Where to go next
- ATL to IAH, every carrier and departure
- IAH to ATL, the return direction
- Delta Air Lines 1601 on the same route75.0%
- Delta Air Lines 1682 on the same route84.5%
- Frontier Airlines 4075 on the same route61.3%
- Delta Air Lines 1585 on the same route82.3%
- Frontier Airlines 1403 on the same route74.7%
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- George Bush Intercontinental (IAH) 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
- How often a connection fails at the major US hubs
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.