April showers are a very British weather phenomena - localised torrential downpours that seem to appear out of nowhere just in time to ruin a sunny spring day. But where exactly do these spontaneous downpours come from?<br /><br />The main cause is a contrast in air temperature at different heights that is particularly distinct in April.<br /><br />The temperature of the air in April is still cool following Winter but the ground has begun to warm up as it is heated by the Spring sunshine - which can be as strong as in late Summer.<br /><br />As the sun heats the ground it sets off rising currents of air.<br /><br />This happens because the air near the ground, warmed by the land is more buoyant than the cold air above it.<br /><br />This leads to more unstable air, which rises rapidly forming clouds and showers.<br /><br />Whilst this happens throughout the year, it is more dramatic in April due to the vertical difference in temperature.
