Carrier route record

F9BWI→MIA

Frontier Airlines · Baltimore to Miami

Flights: 269
Period: September 2025 to August 2026
Share of route: 12%
Carriers: 5

Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Frontier Airlines.

Frontier on BWI to MIA sits in the middle of the pack with a C−. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.3%. The late ones land an hour and a half behind schedule. That rests on 269 flights. The strongest carrier on the route with a full sample, American Airlines, flew 699 at 80.6% on time.

The national on-time rate over the same period is 77.3%, so Frontier on BWI to MIA runs 6 points behind the country as a whole. Across a thousand flights that is about 62 extra late arrivals.

On time

71.1%

Arrivals under 15 minutes late, of 256 completed flights

Avg delay

87 min

Across delayed arrivals only, not all flights

Cancelled

4.46%

National rate is 1.89%

Whole route

75.3%

Every carrier on BWI to MIA, 2,294 flights

These figures cover 269 flights between September 2025 and August 2026. Beyond the headline rate, 11.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally.

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Carrier by carrier

Frontier against every carrier on BWI to MIA

Frontier flew 269 of the 2,294 flights on BWI to MIA, about 12% of it. Its 71.1% on time is 4 points worse than the route as a whole, which runs 75.3%. Ranked by on-time rate it is number four of five carriers on the route, where the range runs from Envoy at 81.8% to Spirit at 60.0%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. American Airlines arrives on time 80.6% of the time; Southwest Airlines manages 72.6%. Sample sizes sit next to every figure, because a two-point gap across 1,189 flights means less than a ten-point one.

On-time performance by carrier on BWI to MIA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Envoy Airthin sample	121	81.8%	64 min	0.00%	B+
American Airlines	699	80.6%	117 min	2.29%	B
Southwest Airlines	1,189	72.6%	53 min	2.27%	C
Frontier Airlines (this page)thin sample	269	71.1%	87 min	4.46%	C−
Spirit Airlinesthin sample	16	60.0%	46 min	6.25%	D−

American leads Southwest by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

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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 33 points, against 8 points between the best and worst carrier.

5am–8am—
8am–11am45 flights88.1%
11am–2pm43 flights90.2%
2pm–5pm21 flights—
5pm–8pm127 flights57.4%
8pm–5am33 flights78.1%

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 57.4% on time, against 90.2% for the 11am–2pm 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 127 flights scheduled in it.

Across the year

Frontier on BWI to MIA through the year

Jul–Sep 202521 flights—
Oct–Dec 202556 flights77.8%
Jan–Mar 202660 flights76.8%
Apr–Jun 202670 flights64.7%
Jul–Sep 202662 flights56.1%

Scale runs 50% 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 71.1% on time across 269 flights.

Frontier on BWI to MIA did not run the same all year. Its best quarter was Oct–Dec 2025 at 77.8% on time and its weakest Jul–Sep 2026 at 56.1%, a swing of 22 points on roughly 67 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 85.0% on time and Friday the weakest at 61.7%, a spread of 23 points.

Arrival by arrival

How late Frontier on BWI to MIA runs when it is late

Frontier on BWI to MIA often beats the schedule: 102 of 256 completed flights, 40%, arrived 15 minutes or more early. The 74 late arrivals split 17 under half an hour, 27 between 30 and 60 minutes, and 30 an hour or more.

15+ min early102 flights39.8%
Within 15 min80 flights31.3%
15–29 min late17 flights6.6%
30–59 min late27 flights10.5%
1–2 hours late16 flights6.3%
2+ hours late14 flights5.5%

Scale runs 0% to 100%.

Share of 256 completed flights by arrival against schedule.

21 of 86 late departures made up the time and arrived on time, 24% of them. 9 flights left on time and still arrived late.

The worst days

Worst days for Frontier on BWI to MIA

The latest arrival of the period was on 4 July 2026, 14 hours 24 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. On three of the five worst days the largest share was filed as a late-arriving aircraft.

The latest arrivals of Frontier on BWI to MIA in the period
Date	Arrived late by	Largest filed cause
4 July 2026	14 hours 24 minutes	National Airspace System
19 June 2026	6 hours 15 minutes	Late-arriving aircraft
9 November 2025	5 hours 24 minutes	National Airspace System
27 July 2026	4 hours 47 minutes	Late-arriving aircraft
31 January 2026	4 hours 13 minutes	Late-arriving aircraft

Delay causes

Why Frontier runs late on this route

Late-arriving aircraft accounts for 62% of the 6,444 delay minutes carriers reported here, and the remaining four split what is left.

Late-arriving aircraft
62%
National Airspace System
28%
Carrier
9%
Extreme weather
1%

62% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 6,444 reported delay minutes here, that single category outweighs weather by 52 to one. The split is drawn from 6,444 reported delay minutes.

Cancellations run at 4.46%, against 1.89% nationally. That is roughly one flight in twenty cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and stage length

What a delay here costs

11.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection 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.

The return leg runs 72.2% on time across 269 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 269 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 BWI to MIA

Put together: the delay figures matter less here than the 4.46% cancellation rate. A late arrival costs you an hour and a half; a cancelled flight costs you the day. Book the 11am–2pm departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 256 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures