Weathering, both mechanical and chemical, is likely to take place more rapidly in wetter climates. Mechanical and chemical weathering require water to break up rocks into fragments or chemically alter minerals, respectively.
Frost wedging is a major source of mechanical weathering. During this process, water expands when it freezes, causing sedimentary rocks to break apart. Similar processes occur when a rock is repeatedly saturated with water and dried. More cycles of these events result in more weathering. In addition to frost wedges, mechanical weathering can also occur through contraction, which causes rocks to expand and contract in response to temperatures, producing patterns that look similar to those produced by frost wedging.