Theoretically, a climate that changes dramatically with the seasons would have put ancient populations in a evolutionary pressure relative to ability of making good plans and sticking to those plans; maybe somebody has some relevant data upon this subject, as many, many hypothesis on the way climate influences individuals or populations, but only a few stand to the 'field data'.

I remembered about geographical determinism and his followers such as Montesquieu, Herder and so on (you can read this in any textbook on geography))))) but I think it influences not on our characters, it influences on us in general (for example northern people are more reserved than southern)...

There is an easily observable fact that occurs in parts of the world where weather conditions almost unchanged throughout the year. In these areas, people tend to "adapt" to that monotony, also in their way of being.

I mean not just the weather directly affect our mood (as occurs in people that tend to depression) but, because of it, our activity will be conditioned and, therefore, also the way we interact socially, have fun, daily activities and leisure. .. based on this activity conditioned by the weather, our mood or state of mind can be indirectly influenced.

Definitely, that's why I moved from a year round place of extreme humidity to a place like Los Angeles where the climate is temperate and best of all, just dry heat.