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DelayAtlas

Carrier route record

F9FLLORD

Frontier Airlines · Fort Lauderdale to Chicago

Flights
151
Period
July 2025 to June 2026
Share of route
4%
Carriers
5
D−GRADE

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

Frontier on FLL to ORD draws a D−. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is about 2.5 hours behind schedule. Build slack into anything you connect to. That rests on 151 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,479 at 74.7% on time.

United Airlines is the most reliable of the three carriers covered here at 74.7% on time across 1,479 flights.

Key figures

On time

61.1%

Arrivals under 15 minutes late, of 144 completed flights

Avg delay

148 min

Across delayed arrivals only, not all flights

Cancelled

3.31%

National rate is 1.81%

Whole route

69.1%

Every carrier on FLL to ORD, 3,422 flights

These figures cover 151 flights between July 2025 and June 2026. Beyond the headline rate, 22.2% 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 FLL to ORD

Frontier flew 151 of the 3,422 flights on FLL to ORD, about 4% of it. Its 61.1% on time is 8 points worse than the route as a whole, which runs 69.1%. Ranked by on-time rate it is number four of five carriers on the route, where the range runs from United at 74.7% to Southwest at 38.7%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. United Airlines arrives on time 74.7% of the time; Spirit Airlines manages 61.3%. Sample sizes sit next to every figure, because a two-point gap across 913 flights means less than a ten-point one.

On-time performance by carrier on FLL to ORD
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines1,47974.7%81 min0.74%C+
American Airlines84670.0%103 min1.54%C
Spirit Airlines91361.3%73 min3.29%D−
Frontier Airlines (this page)thin sample15161.1%148 min3.31%D−
Southwest Airlinesthin sample3338.7%98 min3.03%F−

Spirit Airlines cancels 3.3% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

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 31 points, against 13 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am
  • 8am–11am48 flights87.2%
  • 11am–2pm12 flights
  • 2pm–5pm19 flights
  • 5pm–8pm29 flights
  • 8pm–5am43 flights56.1%

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

The 8pm–5am window is where this operation falls apart: 56.1% on time, against 87.2% for the 8am–11am 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 8am–11am window is the busiest, with 48 flights scheduled in it.

Across the year

Frontier on FLL to ORD through the year

  • Oct–Dec 202515 flights
  • Jan–Mar 202654 flights46.2%
  • Apr–Jun 202682 flights69.6%

Scale runs 40% to 75%. 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 61.1% on time across 151 flights.

Split by quarter, Frontier on FLL to ORD logged 15 flights in Oct–Dec 2025, 54 flights in Jan–Mar 2026 and 82 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 61.1% annual figure is the one to use.

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 53% of the 8,312 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
    53%
  • Carrier
    32%
  • National Airspace System
    12%
  • Extreme weather
    4%

53% 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 8,312 reported delay minutes here, that single category outweighs weather by 14 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 8,312 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 87.2% on time here.

Cancellations run at 3.31%, against 1.81% nationally. That is about one flight in 30 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

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 22.2% 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 1,182 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 67.6% on time across 151 flights, 6 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 6 points of difference.

One caution: this is a thin sample. 151 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 FLL to ORD

Put together: the delay figures matter less here than the 3.31% cancellation rate. A late arrival costs you about 2.5 hours; a cancelled flight costs you the day. Book the 8am–11am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 144 completed flights over 12 months sit behind that.

Related

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.