Source: Gamemastery Guide.
Each of the standard terrain types varies by climate. Climate differs from weather, though it affects the weather significantly. Climate describes the generally prevailing atmospheric conditions of a particular region on a planet and usually defines the seasonal temperature extremes. Note that weather and temperature can change dramatically between terrains even within a particular climatic zone—a warm summer evening in a temperate grassland may be a bone-chillingly cold night on a temperate mountain.
The following climatic zones are therefore presented as guidelines, from the poles to the equator:
The coldest climates surround the poles. These arctic regions are frequently frozen and covered with snow; they have with bitterly cold, dark winters and cool summers. The types of terrain found in arctic climates range from the taiga (the northern or southernmost forests, which extend to the farthest limit trees can grow) to tundra to trackless snowy steppes. The terrain types can be mountainous and glacier-bound, thickly forested, or flat and snow-covered. Despite the harsh conditions, a variety of hardy creatures live in the arctic.
The temperate zone consists of two major subgroups: oceanic and continental. The coastal oceanic zones enjoy a largely steady temperature, regulated by the weather patterns across the ocean, whereas the inland continental zones are warmer in the summer and colder in the winter. How much warmer and how much colder depends on the various landmasses and prevailing weather patterns. The temperate zone covers fertile farmland, high mountains, verdant forests, grasslands, swamps, and many more terrain types. Temperate lands are highly desirable and travelers must be on the lookout for more than just monsters—brigands prey on caravans, armies wage war, and the politics of kingdoms and duchies make their own troubles.
Warmer than the temperate zone, the subtropics also vary widely in terrain type, from hot deserts to vast savannas to dense, broadleaf forests. Rainfall patterns vary widely in these regions, from dry to humid, and while the subtropics rarely see snow or frost, they can suffer intense cold snaps. As the climate tends toward moderation, the weather in the subtropics depends on the terrain to a greater extent.
The tropics are the hottest part of a planet; lying along the equator, they come directly under the sun’s glare for the entirety of the year. Rather than winter or summer, the tropics have a dry season and a wet season, based on the movement of the rain belt from south to north and back again. Again, however, terrain makes a difference: lush, verdant jungles enjoy frequent rainfall, enormous mountains can sport snow at high altitudes, and the sands of massive deserts shift back and forth on the winds.
Section 15 here.