Carrier route record
F9MIA→BWI
Frontier Airlines · Miami to Baltimore
- Flights
- 265
- Period
- July 2025 to June 2026
- Share of route
- 12%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on MIA to BWI sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 265 flights. The strongest carrier on the route with a full sample, Southwest Airlines, flew 1,180 at 75.1% on time.
The US average over the same twelve months is 77.6%, so there is little to separate Frontier on MIA to BWI from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
74.2%
Arrivals under 15 minutes late, of 260 completed flights
Avg delay
90 min
Across delayed arrivals only, not all flights
Cancelled
1.89%
National rate is 1.81%
Whole route
73.6%
Every carrier on MIA to BWI, 2,284 flights
These figures cover 265 flights between July 2025 and June 2026. Beyond the headline rate, 10.0% 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 MIA to BWI
Frontier flew 265 of the 2,284 flights on MIA to BWI, about 12% of it. Its 74.2% on time is about level with the route as a whole at 73.6%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from Envoy at 90.4% to Spirit at 52.9%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: 6 points 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 |
|---|---|---|---|---|---|
| Envoy Airthin sample | 114 | 90.4% | 49 min | 0.00% | A+ |
| Southwest Airlines | 1,180 | 75.1% | 57 min | 2.03% | B |
| Frontier Airlines (this page)thin sample | 265 | 74.2% | 90 min | 1.89% | C |
| American Airlines | 688 | 69.2% | 58 min | 2.03% | C |
| Spirit Airlinesthin sample | 37 | 52.9% | 107 min | 5.41% | F− |
No carrier stands out. Southwest tops the table at 75.1%, 6 points 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 22 points, against 6 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am48 flights87.0%
- 8am–11am46 flights86.7%
- 11am–2pm36 flights82.9%
- 2pm–5pm120 flights65.5%
- 5pm–8pm6 flights—
- 8pm–5am9 flights—
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 87.0% of the time, against 65.5% for the afternoon window. That is 22 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 120 flights scheduled in it.
Across the year
Frontier on MIA to BWI through the year
- Jul–Sep 202579 flights69.2%
- Oct–Dec 202556 flights78.6%
- Jan–Mar 202660 flights80.7%
- Apr–Jun 202670 flights71.0%
Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.
Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 74.2% on time across 265 flights.
Frontier on MIA to BWI did not run the same all year. Its best quarter was Jan–Mar 2026 at 80.7% on time and its weakest Jul–Sep 2025 at 69.2%, a swing of 12 points on roughly 66 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
Across the week, Thursday is the strongest day at 85.4% on time and Monday the weakest at 68.9%. 17 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. Carrier accounts for 45% of the 6,003 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.
- 45%Carrier
- 32%Late-arriving aircraft
- 20%National Airspace System
- 3%Extreme weather
The largest share of delay minutes, 45%, 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 2,700 of the 6,003 delay minutes reported here. The split is drawn from 6,003 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 87.0% on time here.
Cancellations sit at 1.89% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
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. 10.0% 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 946 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 69.4% on time across 265 flights, 5 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 5 points of difference.
One caution: this is a thin sample. 265 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 MIA to BWI
Put together: treat all of this as provisional. 265 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 74.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 260 completed flights over 12 months sit behind that.
Related
Where to go next
- MIA to BWI, every carrier
- Frontier on BWI to MIA, the return leg
- Envoy Air on MIA to BWI90.4%
- Southwest Airlines on MIA to BWI75.1%
- American Airlines on MIA to BWI69.2%
- Frontier Airlines network-wide record
- Miami International (MIA) 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.