Quote Originally Posted by ascanius View Post
The one thing I'm having trouble understanding is why the majority of rainfall seems to occur during the summer and the dry seasons seem to be during the winter and not the summer. The only thing I can come up with to explain this is that the rain maps are not for summer and winter exactly but for fall and spring. With the summer rain map showing fall and winter shows spring. If this is true than wouldn't this alter how we are getting our climates on the map.
For different reasons:

areas subject to monsoon receive a lot of rain in the summer. Monsoon always occur in summer because it's the result of high temperature over the land and lower temperature over the sea... This only happens in summer
more or less : Am,Aw, Cfa, Cwa, Cwb, Dwa, Dwb and sometimes: BSh and possibly Af
some of these place like southern USA are not officially recognized as having a monsoon but they have the same precipitation pattern

The other thing to consider is that cold air contain less moisture than hot air = less rain when it's cold. And also less evaporation.

A lot of the temperate climates receive rain all year long. Mainly: Af, Cfb, Cfc, Cfa (sometimes), Dfa, Dfb.




Finally, this may not be the perfect answer but it is probably because not all climates have the same number of season. Some have 4, some have 2, and some have only 1 because there is little variation over the course of the year.