Warm-cold temperatures are a sure way to spoil wine.

Warm or cold temperatures are a sure way to spoil wine. Of all the factors influencing the quality of stored wine, temperature is perhaps the most important. The ideal temperature for long-term or short-term wine storage is around 13ºC (55ºF), but this can vary from wine to wine.

Wine should never be kept below -4ºC (25 °F), which can cause wine to freeze, or above 20°C (68°F), which can accelerate the aging process and destroy volatile compounds.

Wine storage temperature should be kept as stable as possible: temperature fluctuations can cause the cork to expand and contract, allowing wine to seep out (or air to seep in) around it.

See also: Wine Storage : Fridge
Wine Storage : Proper bottle position
Wine Storage : Light protection
Wine Storage : Open Bottles

Source: masterclass.com