Originally Posted by
ou81two
Well, when one of your main hubs is San Francisco and it has 0 snowstorms then you get a better on time percentage. Same for ATL, IAH, etc. Most spoiled is Hawaiian Airlines with its Honolulu hub flying mostly to west coast cities. There's a few reasons.
This was recently discussed in an OTP thread. Adding to gcashin's good point about SFO, UA also has hubs in wintry Denver, Chicago and Newark, all of which are busy airports surrounded by congested airspace. Similarly, Westjet has the same hub airports as AC, and Delta hubs in Minneapolis and Salt Lake. All airlines rank higher than AC in OTP.
I'm not sure how ATL factors into the conversation.