With all of the hurricane activity the past two months a lot of customers have asked me to address whether their wine collections would be damaged by a lack of cold storage due to power outage. Our litmus test is to check cases for leaking bottles. Leakage means that the bottle was heated to a point where the liquid expanded (usually around 100°) and pushed through the side of the cork. The leakage itself is not damaging in the short term, but the air that goes back down the same path is. The air promotes acetic acid, which begins breaking the wine down within a few days.
If the temperature was not high enough to cause leakage, it will take weeks of prolonged heat before the wine would be damaged. For most of you, who have your collections inside the house, even without air conditioning the temperature would rarely reach levels where significant damage could occur. If you are like me and keep you wine collection in a cooling unit in the garage, I would consider moving the bottles if the power is out for more than five or six days. I hope this helps put your mind at ease.
Halley’s Comet has had a big impact on history (http://www.scientificamerican.com/gallery/is-seeing-a-comet-like-halley-s-a-once-in-a-lifetime-event/). It comes back once every 86 years.