Route reliability record
CHA→ORD
Chattanooga to Chicago
- Flights
- 953
- Period
- July 2025 to June 2026
- Distance
- 501 mi
- Carriers
- 3
This route carries a cancellation problem, not just a delay problem: 4.1% 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 953 CHA to ORD flights, with a median arrival 2 minutes early.
Best time to fly CHA to ORD: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 83.3% of the time and Saturday flights 81.6%, 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
74 min
Across delayed arrivals only, not all flights
Cancelled
4.09%
National rate is 1.81%
Best carrier
SkyWest
69.7% on time across 510 flights
These figures cover 953 flights between July 2025 and June 2026. Beyond the headline rate, 10.8% 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 CHA to ORD
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 | 75.4% | 58 min | 2.44% | B |
| SkyWest Airlines | 510 | 69.7% | 85 min | 5.10% | C− |
| Republic Airwaysthin sample | 238 | 66.8% | 63 min | 3.36% | 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 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–8am244 flights83.3%
- 8am–11am231 flights78.2%
- 11am–2pm42 flights71.1%
- 2pm–5pm109 flights64.4%
- 5pm–8pm327 flights56.3%
- 8pm–5am—
Scale runs 50% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 56.3% on time, against 83.3% 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 5pm–8pm window is the busiest, with 327 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.
December is the weak month at 63.3% on time, against 84.3% in May. 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. March was the busiest month here, with 157 flights.
Across the week, Saturday is the strongest day at 81.6% on time and Sunday the weakest at 63.6%. 18 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 20,000 reported delay minutes.
- 36%Late-arriving aircraft
- 29%Carrier
- 29%National Airspace System
- 5%Extreme weather
- 0%Security
36% 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 20,000 reported delay minutes here, that single category outweighs weather by 7 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 19,969 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 83.3% on time here.
Cancellations run at 4.09%, 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 actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.8% 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 954 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. 953 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 ORD after this flight
What to do with this
Booking this route
Put together: the delay figures matter less here than the 4.09% 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
CHA to ORD questions
How often is CHA to ORD 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 953 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
How reliable is CHA to ORD 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 CHA to ORD?
The 5am–8am departure window is the strongest at 83.3% on time. The 5pm–8pm window is the weakest at 56.3%, 27 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 December delays on CHA to ORD?
December is the weakest month at 63.3% on time, compared with 84.3% 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
- ORD to CHA — the return legseparate record
- Chicago O'Hare International (ORD) delay statistics
- Envoy Air on CHA to ORD75.4%
- SkyWest Airlines on CHA to ORD69.7%
- Republic Airways on CHA to ORD66.8%
- CHA to DFW, a related route78.6%
- LGA to ORD, a related route67.3%
- CHA to ATL, a related route87.5%
- Envoy Air on-time record75.4%
- SkyWest Airlines on-time record69.7%
- Republic Airways on-time record66.8%
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
Direction matters. CHA to ORD and ORD to CHA 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.