The coasts all over the world have an equable climate. It means that they have no extremes of temperatures. The relative humidity remains high throughout the year and these places are very windy indeed.

The temperatures show a gradual rise in summer and a gradual fall in winter. Since these areas are located very close to big water bodies like oceans and seas, so there moderating influence keep the temperatures quite uniform throughout the year. The reason being that the oceans are heated very slowly and are also cooled gradually due to the peculiar property of water that it takes a much longer time than earth to become hot and once it is hot, it takes a similar longer time to cool. So the places located near the oceans are warmer in winter and cooler in summer than the places located further inland. For instance San Francisco takes full advantage of the ocean in summer and the hottest month there rarely exceeds 65 F (18 C) while at farther inland at Sacramento it is usual to expect temperatures of over 90 F in summer and at Phoenix, Arizona, located very far off from sea, temperatures of over 110 F (43 C) in summer are common!

The second peculiar feature of these climates is the high relative humidity throughout the year. This does not affect the weather much in cooler climates but in hotter ones, it creates suffocating conditions. As the combination of high relative humidity with high temperature increase the heat index, so humans feel very uncomfortable indeed. At Chennai in South East India, the heat index sometimes exceeds 120 F (49 C) in summer due to excessive humidity and very hot temperatures. The risk of sunstroke increases sharply above 110 F so these places are best avoided in summer.

Constant breeze is another feature of these climates. It blows throughout the year and brings some relief from the suffocation. The reason for constant and strong breeze is that during the day, the land heats up quite quickly as compare to the sea and so the air above it becomes light and is lifted above creating a low pressure. The cool moist air of the sea rushes to fill the gap and so we get sea breeze which keeps the day temperature low. At night the reverse phenomenon occurs. The land reradiates its heat to the atmosphere and becomes cooler much quicker than the sea which remains warm. So now the low pressure is over the sea and the wind starts blowing from the land towards the sea and it is called land breeze. In short the coastal places get a reliable breeze all the year round.

This, in short, is a brief overview of the climate to be expected in places located near the oceans.