Newly planted seedlings initially have poor contact between their roots and the soil. This can be further aggravated by low soil temperature, which increases the viscosity of water and thus it's resistance to flow. Higher soil temperature stimulates rapid root development and thus promotes good root-soil contact, which can help alleviate seedling water stress. Low soil temperature at the soil surface increases the risk of frost damage to aerial tissues and is associated with frost heaving, a major cause of seedling mortality. Air temperatures of approximately -3C during the growing season will result in frost damage to foliage or succulent stem tissue.
Solar radiation has the greatest influence of all factors on soil temperature.
Temperature changes are transmitted slowly through very dry or very wet soils.