Carrier route record

F9BWI→DTW

Frontier Airlines · Baltimore to Detroit

Flights: 148
Period: July 2025 to June 2026
Share of route: 7%
Carriers: 5

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

Frontier on BWI to DTW sits in the middle of the pack with a C. Close to three flights in four arrive on time by the DOT's definition, 5 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 148 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 1,204 at 86.8% on time.

The national on-time rate over the same period is 77.6%, so Frontier on BWI to DTW runs 5 points behind the country as a whole. Across a thousand flights that is about 45 extra late arrivals.

On time

73.1%

Arrivals under 15 minutes late, of 145 completed flights

Avg delay

66 min

Across delayed arrivals only, not all flights

Cancelled

2.03%

National rate is 1.81%

Whole route

81.7%

Every carrier on BWI to DTW, 2,257 flights

These figures cover 148 flights between July 2025 and June 2026. Beyond the headline rate, 9.0% 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 BWI to DTW

Frontier flew 148 of the 2,257 flights on BWI to DTW, about 7% of it. Its 73.1% on time is 9 points worse than the route as a whole, which runs 81.7%. Ranked by on-time rate it is last of five carriers on the route, where the range runs from Republic at 92.3% to Frontier at 73.1%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 86.8% of the time; Southwest Airlines manages 75.8%. Sample sizes sit next to every figure, because a two-point gap across 785 flights means less than a ten-point one.

On-time performance by carrier on BWI to DTW
Airline	Flights	On time	Avg delay	Cancelled	Grade
Republic Airwaysthin sample	14	92.3%	17 min	7.14%	A−
Delta Air Lines	1,204	86.8%	103 min	1.66%	A
Spirit Airlinesthin sample	106	77.1%	104 min	0.94%	B+
Southwest Airlines	785	75.8%	57 min	1.91%	B
Frontier Airlines (this page)thin sample	148	73.1%	66 min	2.03%	C

Delta leads Southwest by 11 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Departure window

When Frontier runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 148 flights.

There are not enough flights in each departure window to split Frontier's BWI to DTW record by time of day without the percentages moving on noise. The headline rate of 73.1% is the reliable figure here.

Across the year

Frontier on BWI to DTW through the year

Jul–Sep 202539 flights63.2%
Oct–Dec 202536 flights77.8%
Jan–Mar 202614 flights—
Apr–Jun 202659 flights84.7%

Scale runs 55% to 90%. 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 73.1% on time across 148 flights.

Frontier on BWI to DTW did not run the same all year. Its best quarter was Apr–Jun 2026 at 84.7% on time and its weakest Jul–Sep 2025 at 63.2%, a swing of 22 points on roughly 49 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, Monday is the strongest day at 70.0% on time and Friday the weakest at 59.0%. 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 66% of the 2,577 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.

Late-arriving aircraft
66%
Carrier
21%
National Airspace System
13%
Extreme weather
0%

66% 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 2,577 reported delay minutes here, that single category outweighs weather by 66 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 2,577 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 83.1% on time here.

Cancellations sit at 2.03% 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. 9.0% 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.

At 409 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 8am–11am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 76.9% on time across 150 flights, 4 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 4 points of difference.

One caution: this is a thin sample. 148 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 DTW

Put together: treat all of this as provisional. 148 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 73.1% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 145 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures