Summer is the warmest season of the year, between spring and Autumn.

Summer begins on June 20 or 21, the summer solstice, which has the most daylight of any day in the year. 

Summer is traditionally associated with hot or warm weather. In Mediterranean climates, it is also associated with dry weather, while in other places (particularly in Eastern Asia because of the monsoon) it is associated with rainy weather. The wet season is the main period of vegetation growth within the savanna climate regime. Where the wet season is associated with a seasonal shift in the prevailing winds, it is known as a monsoon.

People generally take advantage of the high temperatures by spending more time outdoors during summer. Activities such as travelling to the beach and picnics occur during the summer months. Sports such as soccer, basketball, football, volleyball, skateboarding, baseball, softball, cricket, tennis and golf  are played.

A period of exceptionally hot weather, often with high humidity, during the summer is called a heat wave. The temperature contrast between summer and the other seasons exists only in middle and high latitudes; temperatures in the equatorial regions generally vary little from month to month. For physical causes of the seasons, see season.