The impacts include increase in drought conditions, aridity, heatwaves, sea level rise. Wind greatly contributes to aridity in tropical deserts. Due to its elevation and aridity, the diurnal temperature variation is substantial. Wide diurnal temperature ranges are regular, due to the aridity and moderately high elevation. Due to the aridity and elevation, diurnal temperature variation is often large, averaging annually. Yet because of the aridity, average diurnal temperature variation exceeds in summer. Land-snails also live in deserts, where they must contend with heat and aridity. The elevation, aridity, and clear skies allow intense radiative cooling, even in midsummer. It is resistant to a high degree of aridity, allowing it to grow in deserts. Conditions are influenced by the aridity and high altitude. Due to its low aridity, the Kalahari supports a variety of flora. The reduced coastal habitat and highly increased aridity probably also contributed. Due to the relative aridity, there are only 4.1 days where 24-hour snowfall exceeds . Crustose lichens prefer sites of lower aridity. This was accompanied by increased aridity.