Find out about high and low pressure systems and how they affect weather in the UK.
Highs and lows are pressure systems that cause the day-to-day changes in the weather. High pressure areas - also known as anticyclones - occur where a large mass of air is sinking. Low pressure areas - known as depressions - occur where the air is rising. Where there are such differences in atmospheric pressure, air will move from areas of high pressure to areas of low pressure, this is what causes wind.
In the following pages we look at the how these highs and lows form and what impact they have winds and the weather conditions that we experience.
Last updated: 30 September 2013