Summer is the warmest of the seasons. During the summer, the planet Earth is angled towards the Sun in a way that provides the northern hemisphere with more sunlight than during other times of the year. 

On the northern hemisphere, the summer months are June, July and August. On the southern hemisphere, the summer months are December, January and February. 

Summer is usually considered to have begun when the average temperature of the month exceeds 10 degrees Celsius.