Route reliability record
HOU→ATL
Houston to Atlanta
- Flights
- 2,917
- Period
- July 2025 to June 2026
- Distance
- 696 mi
- Carriers
- 2
This route lands a B, 2 points better than the national rate of 77.6%. About one flight in five arrive 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 2,917 flights, of which Delta Air Lines flew 1,416 at 84.9% on time.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
79.8%
Arrivals under 15 minutes late, of 2,876 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
1.13%
National rate is 1.81%
Best carrier
Delta
84.9% on time across 1,416 flights
These figures cover 2,917 flights between July 2025 and June 2026. The median arrival is 5 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 HOU to ATL
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 84.9% of the time; Southwest Airlines manages 75.1%. Sample sizes sit next to every figure, because a two-point gap across 1,501 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 1,416 | 84.9% | 97 min | 1.77% | B |
| Southwest Airlines | 1,501 | 75.1% | 49 min | 0.53% | B+ |
Delta leads Southwest by 10 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
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 37 points, against 10 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am445 flights91.2%
- 8am–11am596 flights86.6%
- 11am–2pm554 flights84.9%
- 2pm–5pm462 flights73.8%
- 5pm–8pm721 flights72.3%
- 8pm–5am139 flights54.0%
Scale runs 45% to 95%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 54.0% on time, against 91.2% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5pm–8pm window is the busiest, with 721 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 25 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.
September is the best month on the calendar at 92.4% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. July was the busiest month here, with 275 flights.
Across the week, Wednesday is the strongest day at 82.6% on time and Sunday the weakest at 75.2%. 7 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 46% of the 38,000 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.
- 46%Carrier
- 39%Late-arriving aircraft
- 12%National Airspace System
- 3%Extreme weather
- 0%Security
39% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 38,000 reported delay minutes here, that single category outweighs weather by 15 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 38,299 reported delay minutes.
The largest share of delay minutes, 46%, 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 18,000 of the 38,000 delay minutes reported here.
Cancellations sit at 1.13% against a national 1.81%, which is ordinary. Diversions add another 0.27%.
Connections and stage length
What a delay here actually costs
6.3% 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 are the about an hour kind, which a normal layover absorbs.
The 696 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 runs 80.5% on time across 2,915 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 2,917 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 92.4% on time and March 67.4%, a swing of 25 points. If the dates move at all, move them out of March before you think about anything else. 2,876 completed flights over 12 months sit behind that.
Common questions
HOU to ATL questions
How often is HOU to ATL delayed?
About one flight in five arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 20.2% of the 2,917 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on HOU to ATL?
Delta Air Lines leads at 84.9% on time across 1,416 flights. Southwest Airlines is at the other end on 75.1%, a gap of 10 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on HOU to ATL?
The 5am–8am departure window is the strongest at 91.2% on time. The 8pm–5am window is the weakest at 54.0%, 37 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 March delays on HOU to ATL?
March is the weakest month at 67.4% on time, compared with 92.4% in September. Across the year that is 25 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
- ATL to HOU — the return legseparate record
- William P. Hobby (HOU) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Delta Air Lines on-time record84.9%
- Southwest Airlines on-time record75.1%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. HOU to ATL and ATL to HOU 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.