Anticyclones are areas of high pressure. In the northern hemisphere the wind blows clockwise around the centre of the high. The isobars are widely spread so the wind blows more slowly than in a low. Highs also bring more settled weather, clearer skies, and in summer, sunny warm days.

Winter high pressure systems bring the same calm conditions but this often leads to frosts as there are few clouds to trap the heat at night. High pressure in winter can also produce fog - this and the freezing temperatures can make driving hazardous. Highs tend to stay around for longer than lows and this means that the weather can be unchanged for a week or more.