Flight number record
DL 1151
Delta Air Lines · Atlanta to Milwaukee
- Route
- ATL → MKE
- Departs
- 10:10
- Flights
- 340
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1151, check with Delta Air Lines.
DL 1151 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 12 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 45 minutes. That rests on 340 flights, with a median arrival 7 minutes early.
Set against the rest of the country, DL 1151's record is 12 points better than the US average of 77.6%. That gap is worth roughly 120 fewer late arrivals for every thousand flights.
Key figures
On time
89.6%
Arrivals under 15 minutes late, of 335 completed flights
Avg delay
45 min
Across delayed arrivals only, not all flights
Cancelled
1.47%
National rate is 1.81%
1 hour+ late
1.8%
National rate is 8.1%
These figures cover 340 flights between July 2025 and June 2026. The median arrival is 7 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 1151 flies
DL 1151 flies ATL to MKE without a single fixed slot. Its most common scheduled departure was 10:10, used on 43 of 340 flights, with 10:00 (40 flights) and 10:01 (35 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 10:1043 flights12.6%
- Departs 10:0040 flights11.8%
- Departs 10:0135 flights10.3%
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 10:10 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and DL 1151 runs 6 points better at 89.6%. 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 1151 next to ATL to MKE
Every carrier on ATL to MKE combined arrived on time 83.4% of the time across 2,267 flights, so DL 1151 is 6 points ahead of it. Delta flew 2,205 flights on the same city pair under all its flight numbers, including this one, and those ran 84.2% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1151thin sample | 340 | 89.6% | 45 min | 1.47% | A |
| All Delta Air Lines on ATL–MKE | 2,205 | 84.2% | 51 min | 1.81% | B |
| All carriers on ATL–MKE | 2,267 | 83.4% | 51 min | 1.76% | B |
| Delta Air Lines, whole network | 1,038,570 | 81.6% | 71 min | 1.62% | B |
Across the year
DL 1151 quarter by quarter
Quarter by quarter DL 1151 held fairly steady: 94.3% in Jul–Sep 2025, 84.9% in Oct–Dec 2025, 90.4% in Jan–Mar 2026 and 88.8% in Apr–Jun 2026. A spread of 9 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202587 flights94.3%
- Oct–Dec 202586 flights84.9%
- Jan–Mar 202676 flights90.4%
- Apr–Jun 202691 flights88.8%
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
By weekday, DL 1151 did best on Friday at 95.8% on time and worst on Monday at 80.4%. Each day rests on about 49 flights, so a gap of 15 points is worth noticing but could still narrow in another year.
Delay causes
Why DL 1151 runs late
One category carries most of the weight here. Carrier accounts for 54% of the 1,568 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.
- 54%Carrier
- 31%Late-arriving aircraft
- 9%Extreme weather
- 6%National Airspace System
The largest share of delay minutes, 54%, 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 841 of the 1,568 delay minutes reported here. The split is drawn from 1,568 delay minutes reported on DL 1151.
Cancellations sit at 1.47% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
Badly late arrivals are rare here: only 1.8% land an hour or more behind schedule, against 8.1% 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 669 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.
DL 1151 is not only a ATL to MKE flight. It also flew MKE to ATL (295 flights, 91.1% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.
One caution: this is a thin sample. 340 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.
| Also flown as | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| MKE to ATLthin sample | 295 | 91.1% | 37 min | 0.68% | A+ |
What to do with this
Booking DL 1151
For a booking, DL 1151 has one of the better records a US domestic flight can show: 89.6% on time and 1.47% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- ATL to MKE, every carrier and departure
- MKE to ATL, the return direction
- Delta Air Lines 1268 on the same route81.2%
- Delta Air Lines 2999 on the same route91.6%
- Delta Air Lines 1206 on the same route74.5%
- Delta Air Lines 2152 on the same route84.3%
- Delta Air Lines 1246 on the same route87.8%
- 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.