Since the earth orbits in an ellipse, not a circle

[jaydnul]

doesn't that mean that one hemisphere would have a hotter summer than the other hemisphere and the opposite would have a colder winter? if so, which is which. I am willing to guess the northern hemisphere has the colder winter and southern has the hotter summer.

 

[Drakkith]

You are correct. Currently the Earth is nearer to the Sun when the southern hemisphere is in Summer. Due to precession, this will not always be true though. I think it's important to point out that the temperature varies much less in the southern hemisphere than it does in the northern due to the much greater amount of surface area covered by water. So while the southern hemisphere may have a warmer summer than it would otherwise, it is only a very small difference.

 

[willem2]

doesn't that mean that one hemisphere would have a hotter summer than the other hemisphere and the opposite would have a colder winter? if so, which is which. I am willing to guess the northern hemisphere has the colder winter and southern has the hotter summer.

The southern hemishpere would have the hotter summer AND the colder winter, because the sun is closest to the Earth about 4 januari, in the southern hemisphere summer and the most far away about the fifth of july, in the southern hemishpere winter.

As Drakkith mentioned, The fact that the southern hemisphere has so much more water which is very hard to heat up or cool down produces a much larger opposite effect.