Ouch. I claim the largest swing in a flight. A few years ago I did a February flight Heathrow-Chicago-Honolulu. It was about +3C in London. 8 hours later was -27C in Chicago. After an overnight stop it was a ten hour flight, took off in -27C, landed in Honolulu it was +29C. A 56 degree centigrade change in one ten hour period.