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DelayAtlas

Carrier route record

UAORDBNA

United Airlines · Chicago to Nashville

Flights
1,381
Period
July 2025 to June 2026
Share of route
28%
Carriers
9
CGRADE

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

United on ORD to BNA sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 1,381 flights. The strongest carrier on the route with a full sample, Republic Airways, flew 560 at 76.6% on time.

Republic Airways is the most reliable of the four carriers covered here at 76.6% on time across 560 flights.

Key figures

On time

70.4%

Arrivals under 15 minutes late, of 1,357 completed flights

Avg delay

74 min

Across delayed arrivals only, not all flights

Cancelled

1.67%

National rate is 1.81%

Whole route

68.6%

Every carrier on ORD to BNA, 5,021 flights

These figures cover 1,381 flights between July 2025 and June 2026. Beyond the headline rate, 12.0% 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 ORD to BNA

United flew 1,381 of the 5,021 flights on ORD to BNA, about 28% of it. Its 70.4% on time is 2 points better than the route as a whole, which runs 68.6%. Ranked by on-time rate it is number six of nine carriers on the route, where the range runs from PSA at 100.0% to SkyWest at 61.0%. Four of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. Republic Airways arrives on time 76.6% of the time; SkyWest Airlines manages 61.0%. Sample sizes sit next to every figure, because a two-point gap across 1,467 flights means less than a ten-point one.

On-time performance by carrier on ORD to BNA
AirlineFlightsOn timeAvg delayCancelledGrade
PSA Airlinesthin sample3100.0%0.00%A+
Republic Airways56076.6%56 min1.43%B
Envoy Air78374.8%60 min3.19%C−
Frontier Airlinesthin sample8171.8%71 min3.70%C−
Southwest Airlinesthin sample33870.7%60 min1.18%C
United Airlines (this page)1,38170.4%74 min1.67%C
Spirit Airlinesthin sample2669.2%32 min0.00%C+
American Airlines38263.8%116 min1.83%D
SkyWest Airlines1,46761.0%89 min3.89%D−

SkyWest Airlines cancels 3.9% 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.

Flight by flight

United flight numbers on ORD to BNA

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 31 points, against 16 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am161 flights85.6%
  • 8am–11am262 flights78.5%
  • 11am–2pm143 flights82.1%
  • 2pm–5pm350 flights71.5%
  • 5pm–8pm314 flights56.5%
  • 8pm–5am151 flights54.9%

Scale runs 45% to 90%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 54.9% on time, against 85.6% 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 2pm–5pm window is the busiest, with 350 flights scheduled in it.

Across the year

United on ORD to BNA through the year

On-time rate by calendar month60J80F60M71A68M66J69J81A88S76O60N61D
Darker means more delays. Figures are on-time percentages.September best, January worst

January is the weak month at 59.5% on time, against 87.5% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. April was the busiest month here, with 183 flights.

Across the week, Sunday is the strongest day at 73.0% on time and Friday the weakest at 66.0%. 7 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week67.7Mon71.5Tue72.2Wed70.4Thu66.0Fri72.8Sat73.0Sun
Monday: 67.7 percent on time. Tuesday: 71.5 percent on time. Wednesday: 72.2 percent on time. Thursday: 70.4 percent on time. Friday: 66.0 percent on time. Saturday: 72.8 percent on time. Sunday: 73.0 percent on time

Delay causes

Why United runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 45% of the 30,000 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
    26%
  • National Airspace System
    23%
  • Extreme weather
    6%

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 30,000 reported delay minutes here, that single category outweighs weather by 8 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 29,621 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 85.6% on time here.

Cancellations sit at 1.67% against a national 1.81%, which is ordinary. Diversions add another 0.07%.

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. 12.0% 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.

At 409 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg runs 72.3% on time across 1,380 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 1,381 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 United on ORD to BNA

Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 87.5% on time and January 59.5%, a swing of 28 points. If the dates move at all, move them out of January before you think about anything else. 1,357 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.