Drastic changes in temperature will rapidly ruin bottled wine. Ideal conditions for storage are a steady 7 to 13 degrees C. Although maturation is slower, more complexity will develop. Stored at 20 degrees, wine will mature much faster. No matter what, always keep your wine away from direct light, as ultraviolet rays are particularly harmful.
Some degree of humidity is beneficial for long term storage. Beware of air conditioners, as they actually suck moisture out of the air. Ideal humidity is between 60 – 75%, any higher than that and you could be dealing with a mould problem.
Frequent movement or vibration is another thing that is bad for wine. To ensure secure storage you must keep bottles on their sides to prevent the cork from drying out.