How reliable is Philadelphia International Airport?
Flights from PHL departed within 15 minutes of schedule in 81% of 702,417 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 PHL looks like
On-time departures
across 702,417 flights
Source: BTS Airport Operations · data through 2026-08-08. Role-specific BTS departure history; advisory context, not a guarantee for any flight.
Weather by month
When the weather works for you at Philadelphia
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 · 94/100 favorability
Roughest month
Most disruptive — low visibility & fog, snow · 85/100 favorability
Connecting through PHL
How much layover you really need
Based on 74 sellable domestic itineraries seen through Google Flights. Median observed layover: 144 min.
Based on 36 sellable international itineraries seen through Google Flights. Median observed layover: 57 min.
Observed windows come from normalized SearchAPI / Google Flights itineraries. They are not official airport MCTs. We score every connecting itinerary against conservative connection floors.
The read on PHL
What the numbers say about flying through Philadelphia International Airport
Across official performance history, flights from Philadelphia left within 15 minutes of schedule about 81% of the time over 702,417 flights. That's a solid, better-than-average operational record. Pair it with a moderate cancellation rate of 2.1%. When a departure does run late, the typical delay is around 13 minutes.
On weather, Philadelphia is an unusually calm-weather airport year-round. September is the calmest stretch for flying, scoring 94 out of 100 for favorable conditions, while February is the most disruptive at 85, driven mainly by low visibility & fog and snow. The year is relatively steady, so no single month stands out as one to avoid on weather alone.
If you're connecting through PHL, give yourself room. Real itineraries sold through PHL bottom out around 46 minutes for a domestic connection, and international transfers around 49 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 Philadelphia, 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 PHL
- How reliable is Philadelphia International Airport (PHL)?
- Flights from Philadelphia left within 15 minutes of schedule roughly 81% of the time across 702,417 flights of official history — a solid, better-than-average 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 PHL for good weather?
- September has the calmest flying weather at Philadelphia International Airport. February is the most disruptive, mainly from low visibility & fog and snow.
- How much layover time do you need at PHL?
- Allow at least about 46 minutes for a domestic connection and about 49 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.
Reliability guides
Planning a trip through Philadelphia?
Score real flights to and from PHL on reliability, weather, and connection safety — not just price.