Soil is formed from rocks through weathering. By the action of wind, moisture and rain, rocks break down into smaller pieces. These smaller pieces are further eroded by rain water. Slowly the particles become smaller and smaller and form soil. Rainfall, heat and moisture are the 3 main factors which affect the rate of weathering and soil erosion. Weathering happens more quickly in hot and wet climates. Wind is another major factor affecting soil erosion and rock strength/hardness.