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DelayAtlas

Route reliability record

MDWPHX

Chicago to Phoenix

Flights
2,797
Period
July 2025 to June 2026
Distance
1,444 mi
Carriers
2
BGRADE

This route sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 3 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 2,797 flights, with a median arrival 2 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

Key figures

On time

75.0%

Arrivals under 15 minutes late, of 2,748 completed flights

Avg delay

59 min

Across delayed arrivals only, not all flights

Cancelled

1.50%

National rate is 1.81%

Best carrier

Southwest

75.0% on time across 2,670 flights

These figures cover 2,797 flights between July 2025 and June 2026. The median arrival is 2 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

Carrier by carrier

Which airline is most reliable on MDW to PHX

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 MDW to PHX
AirlineFlightsOn timeAvg delayCancelledGrade
Frontier Airlinesthin sample12775.2%135 min1.57%B
Southwest Airlines2,67075.0%55 min1.50%B

Departure window

The best time of day to leave

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 29 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–8am566 flights88.5%
  • 8am–11am511 flights86.0%
  • 11am–2pm388 flights77.8%
  • 2pm–5pm498 flights70.8%
  • 5pm–8pm469 flights60.3%
  • 8pm–5am365 flights59.9%

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

The 8pm–5am window is where this operation falls apart: 59.9% on time, against 88.5% for the 5am–8am 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 5am–8am window is the busiest, with 566 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 32 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.

On-time rate by calendar month78J82F77M68A78M59J70J84A91S75O77N67D
Darker means more delays. Figures are on-time percentages.September best, June worst

June is the worst month at 58.5% on time, 32 points below September, the best at 90.5%. 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 283 flights.

Across the week, Saturday is the strongest day at 82.0% on time and Sunday the weakest at 70.1%. 12 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week71.6Mon77.4Tue77.5Wed75.4Thu73.1Fri82.0Sat70.1Sun
Monday: 71.6 percent on time. Tuesday: 77.4 percent on time. Wednesday: 77.5 percent on time. Thursday: 75.4 percent on time. Friday: 73.1 percent on time. Saturday: 82.0 percent on time. Sunday: 70.1 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 40,000 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
    45%
  • Carrier
    36%
  • National Airspace System
    15%
  • Extreme weather
    4%
  • Security
    1%

45% 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 40,000 reported delay minutes here, that single category outweighs weather by 11 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 40,432 reported delay minutes.

The largest share of delay minutes, 36%, 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 15,000 of the 40,000 delay minutes reported here.

Cancellations sit at 1.50% against a national 1.81%, which is ordinary. Diversions add another 0.25%.

Connections and stage length

What a delay here actually costs

7.1% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route are the about an hour kind, which a normal layover absorbs.

The 1,444 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 73.1% on time across 2,803 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 2,797 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 90.5% on time and June 58.5%, a swing of 32 points. If the dates move at all, move them out of June before you think about anything else. 2,748 completed flights over 12 months sit behind that.

Common questions

MDW to PHX questions

How often is MDW to PHX delayed?

About one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 25.0% of the 2,797 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

How reliable is MDW to PHX compared with the rest of the country?

75.0% of flights arrive on time here against a national 77.6%, a difference of 3 points against it. That is worth a B on this site's grading scale.

What time of day has the fewest delays on MDW to PHX?

The 5am–8am departure window is the strongest at 88.5% on time. The 8pm–5am window is the weakest at 59.9%, 29 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.

How bad are June delays on MDW to PHX?

June is the weakest month at 58.5% on time, compared with 90.5% in September. Across the year that is 32 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Related

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.