Carrier route record
F9ATL→BWI
Frontier Airlines · Atlanta to Baltimore
- Flights
- 883
- 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 ATL to BWI draws a D. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 883 flights. The strongest carrier on the route with a full sample, Southwest Airlines, flew 1,569 at 78.8% on time.
The national on-time rate over the same period is 77.6%, so Frontier on ATL to BWI runs 16 points behind the country as a whole. Across a thousand flights that is about 165 extra late arrivals.
Key figures
On time
61.1%
Arrivals under 15 minutes late, of 864 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
1.93%
National rate is 1.81%
Whole route
75.6%
Every carrier on ATL to BWI, 5,414 flights
These figures cover 883 flights between July 2025 and June 2026. Beyond the headline rate, 14.8% 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 ATL to BWI
Frontier flew 883 of the 5,414 flights on ATL to BWI, about 16% of it. Its 61.1% on time is 14 points worse than the route as a whole, which runs 75.6%. Ranked by on-time rate it is last of four carriers on the route, where the range runs from Southwest at 78.8% to Frontier at 61.1%. 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 |
|---|---|---|---|---|---|
| Southwest Airlines | 1,569 | 78.8% | 63 min | 2.10% | B |
| Delta Air Lines | 2,824 | 78.3% | 59 min | 1.95% | B |
| Spirit Airlinesthin sample | 138 | 77.8% | 63 min | 1.45% | B |
| Frontier Airlines (this page) | 883 | 61.1% | 70 min | 1.93% | D |
No carrier stands out. Southwest tops the table at 78.8%, half a point clear of the bottom, which is inside the range this kind of sample moves year to year.
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 36 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–8am122 flights86.1%
- 8am–11am82 flights62.5%
- 11am–2pm90 flights74.4%
- 2pm–5pm211 flights60.4%
- 5pm–8pm36 flights50.0%
- 8pm–5am342 flights49.7%
Scale runs 40% to 90%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 49.7% on time, against 86.1% 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 8pm–5am window is the busiest, with 342 flights scheduled in it.
Across the year
Frontier on ATL to BWI through the year
July is the worst month at 40.3% on time, 34 points below September, the best at 74.5%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. June was the busiest month here, with 112 flights.
Across the week, Thursday is the strongest day at 66.4% on time and Sunday the weakest at 55.1%. 11 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 48% of the 24,000 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%Late-arriving aircraft
- 31%Carrier
- 17%National Airspace System
- 4%Extreme weather
48% 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 24,000 reported delay minutes here, that single category outweighs weather by 13 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 23,517 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 86.1% on time here.
Cancellations sit at 1.93% against a national 1.81%, which is ordinary. Diversions add another 0.23%.
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. 14.8% 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 577 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 68.0% on time across 883 flights, 7 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 7 points of difference.
One caution: this is a thin sample. 883 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 ATL to BWI
Put together: treat all of this as provisional. 883 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 61.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 864 completed flights over 12 months sit behind that.
Related
Where to go next
- ATL to BWI, every carrier
- Frontier on BWI to ATL, the return leg
- Southwest Airlines on ATL to BWI78.8%
- Delta Air Lines on ATL to BWI78.3%
- Spirit Airlines on ATL to BWI77.8%
- Frontier Airlines network-wide record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Baltimore/Washington International Thurgood Marshall (BWI) 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.