When the earth rotates and your facing the sun.
In the summer
No, they happen all the year round (they depend on the activity of the Sun) but because in summer the skys at night are light not dark, you can not see the faint aurora in summer.
Tornadoes happen mostly during the spring and early summer and during the later afternoon or early evening.
Nothing special.
Yes, though they are most common in spring and summer.
Tornadoes happen in the summer every year.
Underbar Summer happened in 2005.
Summer of the Shark happened in 2001.
Summer Athletics happened in 360.
Summer Games happened in 1984.
Hourglass of Summer happened in 2002.
Summer Days happened in 2006.
Summer will get slammed.
In the summer
I believe that they happen mostly in summer. Summer is hurricane-season.
Summer Games II happened in 1985.
The time frames for summer sessions at schools vary.