Route reliability record
ATL→PIT
Atlanta to Pittsburgh
- Flights
- 2,777
- Period
- July 2025 to June 2026
- Distance
- 526 mi
- Carriers
- 2
This route earns a B. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 2,777 flights, with a median arrival 6 minutes early.
Set against the rest of the country, this route's record is 7 points better than the US average of 77.6%. That gap is worth roughly 69 fewer late arrivals for every thousand flights.
Key figures
On time
84.5%
Arrivals under 15 minutes late, of 2,718 completed flights
Avg delay
55 min
Across delayed arrivals only, not all flights
Cancelled
2.02%
National rate is 1.81%
Best carrier
Delta
84.9% on time across 2,475 flights
These figures cover 2,777 flights between July 2025 and June 2026. The median arrival is 6 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.
Carrier by carrier
Which airline is most reliable on ATL to PIT
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 2,475 | 84.9% | 55 min | 2.22% | B |
| Southwest Airlinesthin sample | 302 | 81.7% | 55 min | 0.33% | B+ |
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 14 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am255 flights92.3%
- 8am–11am404 flights91.2%
- 11am–2pm492 flights90.1%
- 2pm–5pm695 flights82.3%
- 5pm–8pm396 flights78.0%
- 8pm–5am535 flights78.5%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 92.3% of the time, against 78.0% for the evening window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 695 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 13 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
December is the weak month at 76.8% on time, against 89.4% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. October was the busiest month here, with 251 flights.
Across the week, Wednesday is the strongest day at 90.6% on time and Sunday the weakest at 78.4%. 12 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Carrier accounts for 48% of the 23,000 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.
- 48%Carrier
- 31%Late-arriving aircraft
- 16%National Airspace System
- 5%Extreme weather
- 1%Security
The largest share of delay minutes, 48%, 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 11,000 of the 23,000 delay minutes reported here. The split is drawn from 23,113 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 92.3% on time here.
Cancellations sit at 2.02% against a national 1.81%, which is ordinary. Diversions add another 0.11%.
Connections and stage length
What a delay here actually costs
Badly late arrivals are rare here: only 4.4% 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 526 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.
The return leg is a different operation and performs like one: it runs 90.3% on time across 2,777 flights, 6 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 6 points of difference.
The sample behind these figures is 2,777 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 89.4% on time and December 76.8%, a swing of 13 points. If the dates move at all, move them out of December before you think about anything else. 2,718 completed flights over 12 months sit behind that.
Common questions
ATL to PIT questions
How often is ATL to PIT delayed?
About one flight in six arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 15.5% of the 2,777 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is ATL to PIT compared with the rest of the country?
84.5% of flights arrive on time here against a national 77.6%, a difference of 7 points in its favour. That is worth a B on this site's grading scale.
What time of day has the fewest delays on ATL to PIT?
The 5am–8am departure window is the strongest at 92.3% on time. The 5pm–8pm window is the weakest at 78.0%, 14 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are December delays on ATL to PIT?
December is the weakest month at 76.8% on time, compared with 89.4% in September. Across the year that is 13 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- PIT to ATL — the return legseparate record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Pittsburgh International (PIT) delay statistics
- Delta Air Lines on-time record84.9%
- Southwest Airlines on-time record81.7%
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. ATL to PIT and PIT to ATL are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.