summer 1 of 3 noun sum·​mer ˈsə-mər 1 : the season between spring and autumn comprising in the northern hemisphere usually the months of June, July, and August or as reckoned astronomically extending from the June solstice to the September equinox

From Longman Dictionary of Contemporary English Related topics: Nature, Chronology sum‧mer1 /ˈsʌmə $ -ər/ ●●● S1 W1 noun [countable, uncountable] 1 the time of the year when the sun is hottest and the days are longest, between spring and autumn → summery the long hot summer of 1976 The children play on the beach during the summer. in (the) summer Miriam likes to relax in her garden in summer. this/next/last summer We’re going to Italy next summer. a hot summer’s day a sunny summer afternoon a three-week summer vacation early/late summer The tourist season lasts through late summer.