Carrier route record

F9MCO→STL

Frontier Airlines · Orlando to St. Louis

Flights: 394
Period: July 2025 to June 2026
Share of route: 16%
Carriers: 3

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

Frontier on MCO to STL sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 394 flights, with a median arrival 9 minutes early.

The national on-time rate over the same period is 77.6%, so Frontier on MCO to STL runs 5 points behind the country as a whole. Across a thousand flights that is about 47 extra late arrivals.

On time

72.9%

Arrivals under 15 minutes late, of 387 completed flights

Avg delay

97 min

Across delayed arrivals only, not all flights

Cancelled

1.27%

National rate is 1.81%

Whole route

77.0%

Every carrier on MCO to STL, 2,485 flights

These figures cover 394 flights between July 2025 and June 2026. Beyond the headline rate, 15.2% 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 MCO to STL

Frontier flew 394 of the 2,485 flights on MCO to STL, about 16% of it. Its 72.9% on time is 4 points worse than the route as a whole, which runs 77.0%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from Spirit at 100.0% to Frontier at 72.9%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on MCO to STL
Airline	Flights	On time	Avg delay	Cancelled	Grade
Spirit Airlinesthin sample	10	100.0%	—	0.00%	A+
Southwest Airlines	2,081	77.6%	62 min	0.72%	B+
Frontier Airlines (this page)	394	72.9%	97 min	1.27%	C

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 19 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–8am47 flights87.0%
8am–11am21 flights—
11am–2pm36 flights77.8%
2pm–5pm15 flights—
5pm–8pm9 flights—
8pm–5am266 flights68.2%

Scale runs 60% 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 68.2% for the overnight window. That is 19 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 266 flights scheduled in it.

Across the year

Frontier on MCO to STL through the year

Darker means more delays. Figures are on-time percentages.April best, July worst

July is the worst month at 60.0% on time, 22 points below April, the best at 82.4%. 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. March was the busiest month here, with 57 flights.

Across the week, Thursday is the strongest day at 81.2% on time and Sunday the weakest at 64.5%. 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. Late-arriving aircraft accounts for 47% of the 10,000 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.

Late-arriving aircraft
47%
Carrier
45%
Extreme weather
5%
National Airspace System
4%

47% 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 10,000 reported delay minutes here, that single category outweighs weather by 10 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 10,134 reported delay minutes.

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 4,513 of the 10,000 delay minutes reported here.

Cancellations sit at 1.27% against a national 1.81%, which is ordinary. Diversions add another 0.51%.

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. 15.2% 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 882 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 runs 72.6% on time across 395 flights, within half 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. 394 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 MCO to STL

Put together: treat all of this as provisional. 394 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 72.9% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 387 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