the solids have a low specific heat capacity so they can heat themselves speedy with sun radiation.
Water instead has a big specific heat capacity and it can increase its temperature very slowly.
So near the sea you have mild weather both in summer an in winter, both during the night and on the midday.
The difference of heating produce also the wind that pulls from the sea during the day and from the earth during the night.
In the deserts there is earth and air that have no humidity and it heat very fast.
On the sea ( rivers, lakes, places with much vegetation) there is a lot of water that heating itself slowly; at first it becomes vapour, then forms clouds and rain