Route reliability record
BHM→ORD
Birmingham to Chicago
- Flights
- 1,137
- Period
- July 2025 to June 2026
- Distance
- 584 mi
- Carriers
- 4
This route lands a B, level with the national rate of 77.6%. Roughly one flight in four 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 1,137 BHM to ORD flights, with a median arrival 7 minutes early.
Best time to fly BHM to ORD: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 85.0% of the time and Tuesday flights 85.0%, against 77.4% for the route overall.
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
77.4%
Arrivals under 15 minutes late, of 1,118 completed flights
Avg delay
84 min
Across delayed arrivals only, not all flights
Cancelled
1.50%
National rate is 1.81%
Best carrier
Envoy
78.0% on time across 771 flights
These figures cover 1,137 flights between July 2025 and June 2026. Beyond the headline rate, 8.9% 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 BHM 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 |
|---|---|---|---|---|---|
| PSA Airlinesthin sample | 2 | 100.0% | — | 0.00% | A+ |
| Republic Airwaysthin sample | 256 | 84.6% | 71 min | 1.17% | B |
| Envoy Air | 771 | 78.0% | 79 min | 1.43% | B |
| SkyWest Airlinesthin sample | 108 | 55.2% | 112 min | 2.78% | D |
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 23 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–8am430 flights85.0%
- 8am–11am115 flights80.5%
- 11am–2pm249 flights83.3%
- 2pm–5pm106 flights61.9%
- 5pm–8pm235 flights61.8%
- 8pm–5am2 flights—
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 61.8% on time, against 85.0% 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 5am–8am window is the busiest, with 430 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 17 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 68.9% on time, against 86.1% 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. February was the busiest month here, with 124 flights.
Across the week, Tuesday is the strongest day at 85.0% on time and Sunday the weakest at 72.8%. 12 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.
- 35%Late-arriving aircraft
- 27%Carrier
- 25%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 21,150 reported delay minutes.
35% 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 21,000 reported delay minutes here, that single category outweighs weather by 3 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.
Cancellations sit at 1.50% against a national 1.81%, which is ordinary. Diversions add another 0.18%.
Connections and stage length
What a delay here actually costs
8.9% 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 584 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 78.5% on time across 1,137 flights, within about a point 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 1,137 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.
Work out the risk of missing a connection in ORD after this flight
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 86.1% on time and December 68.9%, a swing of 17 points. If the dates move at all, move them out of December before you think about anything else. 1,118 completed flights over 12 months sit behind that.
Common questions
BHM to ORD questions
How often is BHM to ORD delayed?
Roughly one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 22.6% of the 1,137 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is BHM to ORD compared with the rest of the country?
77.4% of flights arrive on time here against a national 77.6%, a difference of half a point against it. That is worth a B on this site's grading scale.
What time of day has the fewest delays on BHM to ORD?
The 5am–8am departure window is the strongest at 85.0% on time. The 5pm–8pm window is the weakest at 61.8%, 23 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 BHM to ORD?
December is the weakest month at 68.9% on time, compared with 86.1% in September. Across the year that is 17 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 BHM — the return legseparate record
- Chicago O'Hare International (ORD) delay statistics
- Republic Airways on BHM to ORD84.6%
- Envoy Air on BHM to ORD78.0%
- SkyWest Airlines on BHM to ORD55.2%
- BHM to ATL, a related route88.3%
- LGA to ORD, a related route67.3%
- BHM to DFW, a related route78.6%
- PSA Airlines on-time record100.0%
- Republic Airways on-time record84.6%
- Envoy Air on-time record78.0%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. BHM to ORD and ORD to BHM 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.