How reliable is Chicago O'Hare International Airport?
Flights from ORD departed within 15 minutes of schedule in 77% of 1,902,692 flights in official BTS history — and weather is calmest in Sep. Here’s the full picture before you book.
Reliability score
on-time, cancellations & delays
Weather favorability
year-round climate
Origin-airport operations
What the departure punctuality at ORD looks like
On-time departures
across 1,902,692 flights
Source: BTS Airport Operations · data through 2026-06-25. Role-specific BTS departure history; advisory context, not a guarantee for any flight.
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Weather by month
When the weather works for you at Chicago
A calm-weather score (0–100) for each month from decades of airport observations — how often conditions disrupt flying, not temperature. Higher is calmer.
Calmest month
Calmest flying weather of the year · 97/100 favorability
Roughest month
Most disruptive — low visibility & fog, snow · 72/100 favorability
Connecting through ORD
How much layover you really need
Allow at least this between domestic flights at ORD. Below it, one small delay risks a misconnect.
International transfers add immigration and bag recheck — give yourself this buffer at ORD or more.
PlaneSane connection-time estimate tuned for ORD's terminal layout. We score every connecting itinerary against conservative connection floors.
The read on ORD
What the numbers say about flying through Chicago O'Hare International Airport
Across official performance history, flights from Chicago left within 15 minutes of schedule about 77% of the time over 1,902,692 flights. That's a respectable but unspectacular operational record. Pair it with a moderate cancellation rate of 2.1%. When a departure does run late, the typical delay is around 16 minutes.
On weather, Chicago is an unusually calm-weather airport year-round. September is the calmest stretch for flying, scoring 97 out of 100 for favorable conditions, while January is the most disruptive at 72, driven mainly by low visibility & fog and snow. The seasonal swing is real but manageable; favor the calmer months when your dates are flexible.
If you're connecting through ORD, give yourself room. A domestic connection wants at least about 50 minutes, and international transfer wants roughly 105 minutes once immigration and a bag recheck are in the mix. Those are floors, not comfortable buffers — one inbound delay can erase them, so add margin when the connection matters.
None of this guarantees your specific flight — it’s the backdrop. To turn it into a booking, score real flights to Chicago, read how we weigh it all in how the PlaneSane Score works, and brush up with how to pick a reliable flight and avoiding weather delays.
Common questions about ORD
- How reliable is Chicago O'Hare International Airport (ORD)?
- Flights from Chicago left within 15 minutes of schedule roughly 77% of the time across 1,902,692 flights of official history — a respectable but unspectacular operational record. The cancellation rate runs about 2.1%. It's advisory context, not a guarantee for any single flight.
- What is the best month to fly from ORD for good weather?
- September has the calmest flying weather at Chicago O'Hare International Airport. January is the most disruptive, mainly from low visibility & fog and snow.
- How much layover time do you need at ORD?
- Allow at least about 50 minutes for a domestic connection and about 105 minutes for an international one as a floor. These are minimums, not comfortable buffers — a single inbound delay can wipe them out, so add margin when you can.
Planning a trip through Chicago?
Score real flights to and from ORD on reliability, weather, and connection safety — not just price.