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DelayAtlas

Carrier route record

UAJAXORD

United Airlines · Jacksonville to Chicago

Flights
893
Period
July 2025 to June 2026
Share of route
43%
Carriers
6
B+GRADE

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

United on JAX to ORD lands a B+, level with the national rate of 77.6%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 893 flights, with a median arrival 5 minutes early.

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

Key figures

On time

77.8%

Arrivals under 15 minutes late, of 884 completed flights

Avg delay

92 min

Across delayed arrivals only, not all flights

Cancelled

0.67%

National rate is 1.81%

Whole route

77.3%

Every carrier on JAX to ORD, 2,062 flights

These figures cover 893 flights between July 2025 and June 2026. Beyond the headline rate, 8.4% 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

United against every carrier on JAX to ORD

United flew 893 of the 2,062 flights on JAX to ORD, about 43% of it. Its 77.8% on time is about level with the route as a whole at 77.3%. Ranked by on-time rate it is number three of six carriers on the route, where the range runs from PSA at 100.0% to SkyWest at 72.2%. Four 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 JAX to ORD
AirlineFlightsOn timeAvg delayCancelledGrade
PSA Airlinesthin sample1100.0%0.00%A+
Republic Airwaysthin sample31779.3%71 min4.73%B−
United Airlines (this page)89377.8%92 min0.67%B+
American Airlines46577.6%126 min2.80%B
Envoy Airthin sample23675.2%67 min0.42%B+
SkyWest Airlinesthin sample15072.2%64 min3.33%C−

Departure window

When United runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 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–8am99 flights90.8%
  • 8am–11am245 flights89.7%
  • 11am–2pm181 flights83.8%
  • 2pm–5pm339 flights63.4%
  • 5pm–8pm29 flights
  • 8pm–5am

Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 90.8% of the time, against 63.4% for the afternoon window. That is 27 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 339 flights scheduled in it.

Across the year

United on JAX to ORD through the year

On-time rate by calendar month65J83F77M84A86M78J60J78A77S92O75N73D
Darker means more delays. Figures are on-time percentages.October best, July worst

July is the worst month at 60.0% on time, 32 points below October, the best at 91.9%. 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 102 flights.

Across the week, Thursday is the strongest day at 81.8% on time and Sunday the weakest at 74.3%. 8 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week74.5Mon80.3Tue75.0Wed81.8Thu79.5Fri79.6Sat74.3Sun
Monday: 74.5 percent on time. Tuesday: 80.3 percent on time. Wednesday: 75.0 percent on time. Thursday: 81.8 percent on time. Friday: 79.5 percent on time. Saturday: 79.6 percent on time. Sunday: 74.3 percent on time

Delay causes

Why United runs late on this route

One category carries most of the weight here. National Airspace System accounts for 45% of the 18,000 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.

  • National Airspace System
    45%
  • Carrier
    29%
  • Late-arriving aircraft
    24%
  • Extreme weather
    2%

45% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 8,124 minutes out of 18,000, against a national NAS share of 21%. The split is drawn from 18,030 reported delay minutes.

Cancellations are rare at 0.67%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and stage length

What a delay here costs

8.4% 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 last an hour and a half, which a normal layover absorbs.

The 864 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 73.6% on time across 893 flights, 4 points below 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. 893 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 United on JAX to ORD

Put together: treat all of this as provisional. 893 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 77.8% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 884 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.