Carrier route record
F9IAD→ATL
Frontier Airlines · Washington to Atlanta
- Flights
- 639
- Period
- July 2025 to June 2026
- Share of route
- 16%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on IAD to ATL sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 8 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 639 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 2,219 at 81.0% on time.
The national on-time rate over the same period is 77.6%, so Frontier on IAD to ATL runs 8 points behind the country as a whole. Across a thousand flights that is about 77 extra late arrivals.
Key figures
On time
69.9%
Arrivals under 15 minutes late, of 624 completed flights
Avg delay
85 min
Across delayed arrivals only, not all flights
Cancelled
2.19%
National rate is 1.81%
Whole route
79.2%
Every carrier on IAD to ATL, 3,976 flights
These figures cover 639 flights between July 2025 and June 2026. Beyond the headline rate, 13.3% 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.
Carrier by carrier
Frontier against every carrier on IAD to ATL
Frontier flew 639 of the 3,976 flights on IAD to ATL, about 16% of it. Its 69.9% on time is 9 points worse than the route as a whole, which runs 79.2%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from Delta at 81.0% to Frontier at 69.9%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: half a point separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 2,219 | 81.0% | 89 min | 2.79% | B |
| United Airlines | 1,097 | 80.9% | 89 min | 0.46% | B+ |
| Republic Airwaysthin sample | 21 | 80.0% | 41 min | 4.76% | B− |
| Frontier Airlines (this page) | 639 | 69.9% | 85 min | 2.19% | C |
No carrier stands out. Delta tops the table at 81.0%, half a point clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
Frontier flight numbers on IAD to ATL
Departure window
When Frontier runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 32 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–8am283 flights66.4%
- 8am–11am44 flights93.2%
- 11am–2pm75 flights83.8%
- 2pm–5pm70 flights61.2%
- 5pm–8pm125 flights63.9%
- 8pm–5am42 flights75.0%
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 93.2% of the time, against 61.2% for the afternoon window. That is 32 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 283 flights scheduled in it.
Across the year
Frontier on IAD to ATL through the year
September is the best month on the calendar at 95.7% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. May was the busiest month here, with 89 flights.
Across the week, Tuesday is the strongest day at 80.3% on time and Sunday the weakest at 62.2%. 18 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Frontier runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 52% of the 16,000 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.
- 52%Late-arriving aircraft
- 26%National Airspace System
- 21%Carrier
- 1%Extreme weather
52% 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 16,000 reported delay minutes here, that single category outweighs weather by 52 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 15,939 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.2% on time here.
Cancellations sit at 2.19% against a national 1.81%, which is ordinary. Diversions add another 0.16%.
Connections and stage length
What a delay here costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 13.3% 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 534 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 63.0% on time across 640 flights, 7 points below 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 7 points of difference.
One caution: this is a thin sample. 639 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 Frontier on IAD to ATL
Put together: treat all of this as provisional. 639 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 69.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 624 completed flights over 12 months sit behind that.
Related
Where to go next
- IAD to ATL, every carrier
- Frontier on ATL to IAD, the return leg
- Delta Air Lines on IAD to ATL81.0%
- United Airlines on IAD to ATL80.9%
- Frontier Airlines network-wide record
- Washington Dulles International (IAD) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.