Route reliability record
ORD→CHA
Chicago to Chattanooga
- Flights
- 954
- Period
- July 2025 to June 2026
- Distance
- 501 mi
- Carriers
- 3
This route carries a cancellation problem, not just a delay problem: 4.7% of scheduled flights never operate, against 1.8% nationally. Of the ones that do fly, about seven flights in ten arrive on time, worth a C− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 954 ORD to CHA flights, with a median arrival 5 minutes early.
Best time to fly ORD to CHA: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 75.0% of the time and Tuesday flights 73.6%, against 70.2% for the route overall.
The national on-time rate over the same period is 77.6%, so this route runs 7 points behind the country as a whole. Across a thousand flights that is about 74 extra late arrivals.
Key figures
On time
70.2%
Arrivals under 15 minutes late, of 907 completed flights
Avg delay
79 min
Across delayed arrivals only, not all flights
Cancelled
4.72%
National rate is 1.81%
Best carrier
SkyWest
69.0% on time across 510 flights
These figures cover 954 flights between July 2025 and June 2026. Beyond the headline rate, 11.8% 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
Which airline is most reliable on ORD to CHA
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Airthin sample | 205 | 77.3% | 78 min | 3.41% | B− |
| SkyWest Airlines | 510 | 69.0% | 78 min | 5.29% | C− |
| Republic Airwaysthin sample | 239 | 66.7% | 83 min | 4.60% | C− |
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 10 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–8am64 flights75.0%
- 8am–11am128 flights72.5%
- 11am–2pm27 flights—
- 2pm–5pm310 flights70.3%
- 5pm–8pm234 flights64.7%
- 8pm–5am191 flights73.3%
Scale runs 55% to 80%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 64.7% on time, against 75.0% 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 310 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 21 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.
May is the best month on the calendar at 82.7% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. March was the busiest month here, with 157 flights.
Across the week, Tuesday is the strongest day at 73.6% on time and Sunday the weakest at 58.8%. 15 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
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 21,000 reported delay minutes.
- 41%Carrier
- 28%Late-arriving aircraft
- 18%National Airspace System
- 13%Extreme weather
Extreme weather accounts for 13% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.1 times the usual weather exposure. The split is drawn from 21,432 reported delay minutes.
The largest share of delay minutes, 41%, 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 8,869 of the 21,000 delay minutes reported here.
Cancellations run at 4.72%, against 1.81% nationally. That is about one flight in twenty 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 actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.8% 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 501 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 70.2% on time across 953 flights, within half 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. 954 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.
Work out the risk of missing a connection in CHA after this flight
What to do with this
Booking this route
Put together: the delay figures matter less here than the 4.72% cancellation rate. A late arrival costs you a little over an hour; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 907 completed flights over 12 months sit behind that.
Common questions
ORD to CHA questions
How often is ORD to CHA delayed?
Roughly one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 29.8% of the 954 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is ORD to CHA compared with the rest of the country?
70.2% of flights arrive on time here against a national 77.6%, a difference of 7 points against it. That is worth a C− on this site's grading scale.
What time of day has the fewest delays on ORD to CHA?
The 5am–8am departure window is the strongest at 75.0% on time. The 5pm–8pm window is the weakest at 64.7%, 10 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 March delays on ORD to CHA?
March is the weakest month at 61.5% on time, compared with 82.7% in May. Across the year that is 21 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
- CHA to ORD — the return legseparate record
- Chicago O'Hare International (ORD) delay statistics
- Envoy Air on ORD to CHA77.3%
- SkyWest Airlines on ORD to CHA69.0%
- Republic Airways on ORD to CHA66.7%
- ORD to LGA, a related route67.3%
- DFW to CHA, a related route72.9%
- ORD to BOS, a related route67.6%
- Envoy Air on-time record77.3%
- SkyWest Airlines on-time record69.0%
- Republic Airways on-time record66.7%
- The US routes with the most cancellations
- The best time of day to fly, according to 7.04 million flight records
Direction matters. ORD to CHA and CHA to ORD are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.