- 4 seasons; coldest in winter, hotter in summer and then cools down through autumn
- 5' in January and 20' in August
- Winds are mostly warm south westerlies, cold north winds are also common
- High rainfall all year round
- Artic maritime: forms over the Artic ocean, brings very cold and wet air
- Polar continental: forms over Siberia, brings cold dry air, can bring snow if the air picks up moisture from the North Sea
- Tropical continental: forms over Africa, brings warm, dry air
- Tropical maritime: forms over Atlantic ocean, brings warm wet air
- Polar maritime: forms over North Atlantic ocean, brings cold, wet air
Depressions
- LOW PRESSURE SYSTEM often below 1,000 mb
- A depression is an area of relatively low atmospheric pressure and is recognised on a weather map by a system of closed isobars with pressure decreasing towards the centre
- Isobars will be close together producing a steep pressure gradient, creating strong winds that flow anticlockwise
- Most depressions that affect the UK form over the Atlantic Ocean where the two air masses polar maritime and tropical maritime meet, where cold dense air meets warm light air
- At the polar front the warm air rises above the cooler dense air and as it does this condensation occurs resulting in a band of clouds and precipitation along the front
- Can occur all throughout the year
- HIGH PRESSURE SYSTEM
- Represented on a weather map by a closed system with pressure increasing on isobars towards the centre
- Move slowly and remain stationary over an area for days or even weeks
- The air in an anticyclone subsides, warming as it falls, producing a decrease in humidity and a lack of cloud and dry conditions
- Winds are weak and flow gently in a clockwise direction in northern hemisphere and anticlockwise in the southern hemisphere
- In winter: cold daytime temps, very cold nighttime temps, clear skies some radiation fogs
- In summer: hot daytime temps, warm nighttime temps, clear skies, morning mists, thunderstorms may occur
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