What is the source of BB area creaking associated with ambient temperature changes?
Pressfit BBs are prone to creaking at the best of times. When cold, steel inside aluminium will be tighter than when warm, as the thermal expansion of aluminium is about twice that of steel. The difference is only about 0.001% per degree C, but on something the size of a BB from a cold day to a warm one  that's around 0.1mm, easily the difference between a tight fit and one with some movement.