Flight number record
DL 1151
Delta Air Lines · Atlanta to Milwaukee
- Route
- ATL → MKE
- Departs
- 10:10
- Flights
- 340
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 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 11 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 45 minutes. That rests on 340 flights, with a median arrival 8 minutes early.
Set against the rest of the country, DL 1151's record is 11 points better than the US average of 77.3%. That gap is worth roughly 113 fewer late arrivals for every thousand flights.
Key figures
On time
88.6%
Arrivals under 15 minutes late, of 334 completed flights
Avg delay
44 min
Across delayed arrivals only, not all flights
Cancelled
1.76%
National rate is 1.89%
1 hour+ late
1.8%
National rate is 8.3%
These figures cover 340 flights between September 2025 and August 2026. The median arrival is 8 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 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 10:01 (35 flights) next.
- Departs 10:1043 flights12.6%
- Departs 10:0135 flights10.3%
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 10:10 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and DL 1151 runs 5 points better at 88.6%. 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 1151 next to ATL to MKE
Every carrier on ATL to MKE combined arrived on time 82.8% of the time across 2,264 flights, so DL 1151 is 6 points ahead of it. Delta flew 2,202 flights on the same city pair under all its flight numbers, including this one, and those ran 83.7% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1151thin sample | 340 | 88.6% | 44 min | 1.76% | A |
| All Delta Air Lines on ATL–MKE | 2,202 | 83.7% | 53 min | 1.95% | B |
| All carriers on ATL–MKE | 2,264 | 82.8% | 53 min | 1.90% | B |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 1151 quarter by quarter
Quarter by quarter DL 1151 held fairly steady: 84.9% in Oct–Dec 2025, 90.4% in Jan–Mar 2026, 88.8% in Apr–Jun 2026 and 90.2% in Jul–Sep 2026. A spread of 6 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
- Jul–Sep 202525 flights—
- Oct–Dec 202586 flights84.9%
- Jan–Mar 202676 flights90.4%
- Apr–Jun 202691 flights88.8%
- Jul–Sep 202662 flights90.2%
Scale runs 75% to 95%. Rows with fewer than 30 flights show a dash.
By weekday, DL 1151 did best on Friday at 97.9% on time and worst on Monday at 78.8%. Each day rests on about 49 flights, so a gap of 19 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 1151 runs when it is late
The 38 late arrivals split 17 under half an hour, 15 between 30 and 60 minutes, and 6 an hour or more.
- 15+ min early74 flights22.2%
- Within 15 min222 flights66.5%
- 15–29 min late17 flights5.1%
- 30–59 min late15 flights4.5%
- 1–2 hours late3 flights0.9%
- 2+ hours late3 flights0.9%
Scale runs 0% to 100%.
Share of 334 completed flights by arrival against schedule.
7 of 38 late departures made up the time and arrived on time, 18% of them. 7 flights left on time and still arrived late.
The worst days
Worst days for DL 1151
The latest arrival of the period was on 8 December 2025, 2 hours 33 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 |
|---|---|---|
| 8 December 2025 | 2 hours 33 minutes | Late-arriving aircraft |
| 28 April 2026 | 2 hours 25 minutes | Extreme weather |
| 17 April 2026 | 2 hours 4 minutes | Carrier |
| 7 December 2025 | 1 hour 55 minutes | Carrier |
| 18 January 2026 | 1 hour 21 minutes | Carrier |
Delay causes
Why DL 1151 runs late
Carrier accounts for 55% of the 1,668 delay minutes carriers reported here, and the remaining four split what is left.
- 55%Carrier
- 28%Late-arriving aircraft
- 9%National Airspace System
- 9%Extreme weather
The largest share of delay minutes, 55%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 911 of the 1,668 delay minutes reported here. The split is drawn from 1,668 delay minutes reported on DL 1151.
Cancellations sit at 1.76% against a national 1.89%, 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 8.3% 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 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.
DL 1151 is not only a ATL to MKE flight. It also flew MKE to ATL (295 flights, 90.0% 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 | 90.0% | 43 min | 1.02% | A |
What to do with this
Booking DL 1151
For a booking, read DL 1151 as 88.6% on time with 1.76% cancelled over 340 flights. Those are rates from the past twelve months, not a forecast for any particular 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 route80.9%
- Delta Air Lines 2999 on the same route91.6%
- Delta Air Lines 1206 on the same route74.4%
- Delta Air Lines 2152 on the same route83.6%
- Delta Air Lines 1246 on the same route89.4%
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Milwaukee Mitchell International (MKE) 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 to read this site: grades, sample sizes, and honest caveats
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.