Photographs of a Coastal Environment and Desert Environment are shown. A representative graduated thermometer is displayed adjacent to each photograph. The thermometer shows the Temperature Variation as the day and night progresses. In the case of the Coastal Environment, the temperature increases as the day progresses from low temperature at the start of sunrise to moderately high temperature at the start of sunset and then the temperature decreases as the night progresses from moderately high temperature at the start of sunset to low temperature at the start of the sunrise. In the case of the Desert Environment, the temperature increases as the day progresses from moderately high temperature at the start of sunrise to extremely high temperature at the start of sunset and then the temperature decreases as the night progresses from extremely high temperature at the start of the sunset to moderately high temperature at the start of the sunrise.
With its oceans, Earth has a milder climate than a dry planet. You see the same effect in comparing seacoasts with the desert. This is due to water's high specific heat—water can gain or lose heat with little change in temperature, because much of the heat is used to break hydrogen bonds. At night, hydrogen bonds return, releasing heat so the temperature does not drop far.