a cold day in July

Etymology
From July being on average the hottest month in the Northern Hemisphere.

Noun

 * 1)  The time of occurrence of an event that will never happen.
 * It'll be a cold day in July when that happens.

Translations

 * Chinese:
 * Mandarin: 绝不可能, 绝无可能
 * French:, ,
 * German:, , am Sankt Nimmerleinstag
 * Italian: alle calende greche, quando gli asini voleranno,
 * Portuguese: dia de São Nunca
 * Turkish:, iki cihan bir araya gelince,