Language is not inherited biologically. It is a cultural phenomenon, it is inherited through culture.
The climate of an area has very little to do with the language spoken in that area. What counts is the history of the region, who conquered it last, what was their cultural level, how many people they brought in and so on.
Languages, at least successful languages, do not remain fixed in the place they were born, like plants. They spread, they move, they evolve. English was born on a cold, foggy and rainy island; but it is now spoken in sunny California, and in parched Australia, and in frigid Alaska. French was born in the sweet heart of France, blessed by the mildest climate of all Europe; but it is now spoken from Montreal in Quebec, to Cayenne in French Guiana, to Brazzaville in Congo. Russian is spoken over an unimaginably large territory, from the Pontic Steppe in the south-west to the Siberian taiga in the north-east, comprising fertile plains, and unforgiving steppes, and rugged mountains and whatever have you.
So here we are: three examples of languages spoken over every imaginable climate and geography. And what do those examples show? They show that the climate of a district is irrelevant when it comes to finding out what language is spoken there. What counts is its history.
Consider the perfect example: Asia Minor, known as Anatolia nowadays.
What languages are spoken in Asia Minor?
Well, it all depends on when.
There were the Anatolian languages, Hittite, and Luwian and Lycian and so on; and there was Phrygian; and there was Armenian. And we know that those languages were not autochthonous, for they are Indo-European languages, and we even have direct references in ancient Hittite texts to a previous language which had been replaced by Hittite. And then came the Greeks, and Asia Minor spoke Greek, a language quite unlike the languages it replaced. And then came the Turks, and nowadays Asia Minor speaks Turkish, a language utterly unlike Greek. So that, the supposed influence of the climate of Asia Minor becomes irrelevant when compared to the overwhelming importance of history.