The land of Skyrim is the most rugged on the continent, containing four of the five highest peaks in Tamriel (see Places of Note: Throat of the World). Only in the west do the mountains abate to the canyons and mesas of the Reach, by far the most cosmopolitan of the Holds of Skyrim, Nords of the pure blood holding only the barest majority according to the recent Imperial Census. The rest of Skyrim is a vertical world: the high ridges of the northwest-to-southeast slanting mountain ranges, cleft by deep, narrow valleys where most of the population resides. Along the sides of the river valleys, sturdy Nord farmers raise a wide variety of crops; wheat flourishes in the relatively temperate river bottoms, while only the snowberry bushes can survive in the high orchards near the treeline. The original Nord settlements were generally established on rocky crags overlooking a river valley; many of these villages still survive in the more isolated Holds, especially along the Morrowind frontier. In most of Skyrim, however, this defensive posture was deemed unnecessary by the mid-first era, and most cities and towns today lie on the valley floors, in some cases still overlooked by the picturesque ruins of the earlier settlement.
Nords are masters of wood and timber construction; many structures survive in use today that were built by the first settlers over 3,000 years ago. A fine example of Nord military engineering can be seen at Old Fort, one of the royal bastions constructed by the First Empire to guard its southern frontier. Towering walls of huge, irregular porphyry blocks fit together without seam or mortar, as if constructed by mythical Elhnofey rather than men.
The nine Holds present a varied aspect in people, government, and trade. The Reach could be mistaken for one of the petty kingdoms of High Rock; it is full of Bretons, Redguards, Cyrodiils, Elves of all stripes, and even a few misplaced khajiit. The northern and western Holds -- Winterhold, Eastmarch, Rift, and the Pale, known collectively as the Old Holds -- remain more isolated, by geography and choice, and the Nords there still hold true to the old ways. Outsiders are a rarity, usually a once-yearly visit from an itinerant peddler. The young men go out for weeks into the high peaks in the dead of winter, hunting the ice wraiths that give them claim to full status as citizens (a laudable practice that could serve as a model for the more "civilized" regions of the Empire). Here, too, the people still revere their hereditary leaders, while the other Holds have long been governed (after a fashion) by elected moots. It is fortunate for Skyrim and the Septim Empire that the people of the Old Holds have preserved the traditions of their forefathers.
From:
http://www.imperial-library.info/content/pocket-guide-empire-first-edition-skyrim
Don'tworry, Skrim should have many temperate and lush areas. Only the mountainous areas of the south should be really snowy.