{n. phr.} The hottest days of the year in the Northern Hemisphere (July and August). (The ancient Romans associated this time with the "Dog Star" - Sirius - which becomes visible in the heavens at this time of year.) * /"The dog days are upon us," John said. "It's time to go swimming in the lake."/
DOG DAYS
Meaning of DOG DAYS in English
Dictionary of English idioms . Словарь английских идиом. 2012