Earth Science questions!? Help please.?

The word "average" is what causes the problems.

You can have an extremely variable climate, say one that freezes in the winter and is very hot in the summer. The average temperature would give a false sense of what the climate is like. It takes all the highs and lows and smooths them out (mathematically that is). On the other hand, a climate that is very moderate (not very hot, not very cold) could end up with a similar average temperature. Comparing annual average temperature is useful in some instances, but for comparing local climates it can be very misleading.

Simple example:

Climate Zone 1 has 6 months of 100 degree F highs, and 6 months of 0 degree F days. The average temperature would be 50 degrees F.

Climate Zone 2 has 6 months of 60 degree F highs, and 6 months of 40 degrees F highs. Again, the average is 50 degrees F.

The same could happen with rainfall averages. One area may get light rain showers spread throughout the year (like in Zone 2 above), but a different one could have a very dry summer and a wet winter that makes up for it (like in Zone 1 above).

Averages can be tricky that way.