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DelayAtlas

Carrier route record

F9PHXORD

Frontier Airlines · Phoenix to Chicago

Flights
203
Period
July 2025 to June 2026
Share of route
4%
Carriers
4
C−GRADE

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

Frontier on PHX to ORD sits in the middle of the pack with a C−. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land close to two hours behind schedule. That rests on 203 flights. The strongest carrier on the route with a full sample, American Airlines, flew 2,994 at 78.7% on time.

American Airlines is the most reliable of the three carriers covered here at 78.7% on time across 2,994 flights.

Key figures

On time

68.8%

Arrivals under 15 minutes late, of 192 completed flights

Avg delay

122 min

Across delayed arrivals only, not all flights

Cancelled

3.94%

National rate is 1.81%

Whole route

76.4%

Every carrier on PHX to ORD, 5,593 flights

These figures cover 203 flights between July 2025 and June 2026. Beyond the headline rate, 14.1% 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 PHX to ORD

Frontier flew 203 of the 5,593 flights on PHX to ORD, about 4% of it. Its 68.8% on time is 8 points worse than the route as a whole, which runs 76.4%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from American at 78.7% to Southwest at 60.8%.

The choice of carrier is not cosmetic here. American Airlines arrives on time 78.7% of the time; Southwest Airlines manages 60.8%. Sample sizes sit next to every figure, because a two-point gap across 459 flights means less than a ten-point one.

On-time performance by carrier on PHX to ORD
AirlineFlightsOn timeAvg delayCancelledGrade
American Airlines2,99478.7%75 min2.24%B
United Airlines1,93777.3%82 min0.52%B+
Frontier Airlines (this page)thin sample20368.8%122 min3.94%C−
Southwest Airlines45960.8%67 min1.31%D

The spread between American and Southwest is 18 points, wide enough that it should decide the booking. On a hundred trips that is 18 more arrivals inside the on-time window.

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 28 points, against 18 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am16 flights
  • 8am–11am39 flights69.4%
  • 11am–2pm57 flights75.0%
  • 2pm–5pm29 flights
  • 5pm–8pm49 flights46.7%
  • 8pm–5am13 flights

Scale runs 40% to 80%. Rows with fewer than 30 flights show a dash.

The 5pm–8pm window is where this operation falls apart: 46.7% on time, against 75.0% 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 11am–2pm window is the busiest, with 57 flights scheduled in it.

Across the year

Frontier on PHX to ORD through the year

  • Jul–Sep 202538 flights62.9%
  • Oct–Dec 202550 flights73.9%
  • Jan–Mar 202690 flights64.4%
  • Apr–Jun 202625 flights

Scale runs 55% to 80%. 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 68.8% on time across 203 flights.

Frontier on PHX to ORD did not run the same all year. Its best quarter was Oct–Dec 2025 at 73.9% on time and its weakest Jul–Sep 2025 at 62.9%, a swing of 11 points on roughly 68 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 75.0% on time and Monday the weakest at 64.3%. 11 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Frontier runs late on this route

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 7,299 reported delay minutes.

  • Carrier
    35%
  • Late-arriving aircraft
    35%
  • National Airspace System
    20%
  • Extreme weather
    10%

35% 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 7,299 reported delay minutes here, that single category outweighs weather by 3 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 7,299 reported delay minutes.

The largest share of delay minutes, 35%, 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 2,586 of the 7,299 delay minutes reported here.

Cancellations run at 3.94%, against 1.81% nationally. That is about one flight in 25 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. 14.1% 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 1,440 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 67.5% on time across 203 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. 203 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 PHX to ORD

Put together: the delay figures matter less here than the 3.94% cancellation rate. A late arrival costs you close to two hours; 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. 192 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.