Why is it hotter in summer?
What causes it to be hotter in summer is that the earth is tilted on its axis. This means that when the southern hemisphere is tilted towards the sun there are more hours of daylight and the sun appears more directly overhead - so concentrating the heat and giving longer each day for us to warm up. When our part of the earth is tilted away from the sun days are shorter, less direct light reaches us,and we get the coldness of winter.