Wind is one of the most important elements that can affect the surfing conditions. Wind forms waves and controls the size and direction of ocean swells. Surfers generally talk in terms of 'onshore and offshore' winds. Winds are generated by differences in temperature and pressure. The onshore, offshore effect is created because the land heats up and cools down much faster than water, creating pressure differences and wind as shown in Figure 1.13. 

Onshore

Onshore winds generally make the wave face crumble and too mushy for surfing. They tend to break up the formed swell lines and make the surf look jumbled and messy. (Figure 1.14).

 
Offshore

An offshore wind blows from the land out to sea. This makes the wave face clean and easy to ride. Offshore conditions are ideal for surfing (Figure 1.15).

 
Weather patterns

The ocean is an unstable and constantly changing enviroment. To be a good surfer and to score the right surfing conditions takes a working knowledge of the weather. As stated above it is changes in pressure that creates wind, and in turn, waves.

By using the weather charts a surfer can determine wind and swell direction. The lines connecting places of equal air pressure are called 'isobars'. The 'L' represents a low pressure system the 'H' represents a high pressure system. The winds circulate in a clockwise direction around the low-pressure and anticlockwise around a high-pressure system. Low-pressure systems can intensify to form tropical cyclones.

A weather chart like the one shown in figure 1.12 tells a surfer when the best surfing conditions occur. The high pressure in Western Australia is producing offshore winds in Perth, and the low moving towards NZ will produce high winds and large surf on the west coast.