Flight number record
F9 4075
Frontier Airlines · Atlanta to Houston
- Route
- ATL → IAH
- Departs
- 21:15
- Flights
- 334
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s F9 4075, check with Frontier Airlines.
F9 4075 draws a D. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is an hour and a half behind schedule. Build slack into anything you connect to. That rests on 334 flights, with a median arrival 1 minute early.
The national on-time rate over the same period is 77.6%, so F9 4075 runs 14 points behind the country as a whole. Across a thousand flights that is about 142 extra late arrivals.
Key figures
On time
63.4%
Arrivals under 15 minutes late, of 328 completed flights
Avg delay
92 min
Across delayed arrivals only, not all flights
Cancelled
1.80%
National rate is 1.81%
1 hour+ late
18.6%
National rate is 8.1%
These figures cover 334 flights between July 2025 and June 2026. Beyond the headline rate, 18.6% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Schedule
When F9 4075 flies
F9 4075 flies ATL to IAH without a single fixed slot. Its most common scheduled departure was 21:15, used on 71 of 334 flights, with 21:25 (57 flights) and 21:30 (43 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 21:1571 flights21.3%
- Departs 21:2557 flights17.1%
- Departs 21:3043 flights12.9%
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 21:15 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.5%, and F9 4075 runs 7 points worse at 63.4%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
Against the route
F9 4075 next to ATL to IAH
Every carrier on ATL to IAH combined arrived on time 76.4% of the time across 4,914 flights, so F9 4075 is 13 points behind it. Frontier flew 767 flights on the same city pair under all its flight numbers, including this one, and those ran 68.9% on time. Across its whole network Frontier Airlines managed 73.2%, which this flight trails by 10 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| F9 4075thin sample | 334 | 63.4% | 92 min | 1.80% | D |
| All Frontier Airlines on ATL–IAH | 767 | 68.9% | 82 min | 1.43% | C |
| All carriers on ATL–IAH | 4,914 | 76.4% | 67 min | 1.87% | B |
| Frontier Airlines, whole network | 205,332 | 73.2% | 84 min | 1.85% | C |
Across the year
F9 4075 quarter by quarter
Quarter by quarter F9 4075 held fairly steady: 59.3% in Jul–Sep 2025, 59.7% in Oct–Dec 2025, 65.5% in Jan–Mar 2026 and 68.6% 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 202582 flights59.3%
- Oct–Dec 202577 flights59.7%
- Jan–Mar 202686 flights65.5%
- Apr–Jun 202689 flights68.6%
Scale runs 50% to 75%. Rows with fewer than 30 flights show a dash.
By weekday, F9 4075 did best on Thursday at 75.0% on time and worst on Friday at 56.9%. Each day rests on about 48 flights, so a gap of 18 points is worth noticing but could still narrow in another year.
Delay causes
Why F9 4075 runs late
One category carries most of the weight here. Late-arriving aircraft accounts for 50% of the 11,000 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.
- 50%Late-arriving aircraft
- 45%Carrier
- 4%National Airspace System
- 1%Extreme weather
50% 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 11,000 reported delay minutes here, that single category outweighs weather by 50 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 11,017 delay minutes reported on F9 4075.
Cancellations sit at 1.80% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 18.6% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum 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. 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.
Every one of the 334 flights under F9 4075 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. 334 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 F9 4075
For a booking, F9 4075 is a flight to put a long connection behind. 18.6% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.
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 route74.8%
- Delta Air Lines 1284 on the same route73.6%
- Delta Air Lines 1682 on the same route82.1%
- Delta Air Lines 1585 on the same route81.2%
- Frontier Airlines 1403 on the same route72.3%
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- Frontier Airlines on-time record
- Every Frontier Airlines flight number with a record
- The most and least reliable flight numbers in the US
- Why the first flight of the morning is statistically safest
A flight number here means Frontier Airlines’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.