Britain & Western Europe’s weather and climate

Britain has a Cool Temperate Humid (Maritime) Climate. Features of this climate are:

• it is typically found in the mid-latitudes 40° and 60°N (or S)
• marine influences are predominant, and can influence areas far inland
• eastward-moving air bringing depressions (cyclonic conditions) with characteristics of temperature and humidity derived from the oceans
• the weather can be extremely changeable and variable (e.g. continental high pressure extends at times causing severe cold and within hours southwesterly flow is re-established and warm damp conditions reappear)
• winters are mild, the oceans effect is marked
• summers are warm, 13° to 18°C is common in July (the oceans can cool summer temperatures too)
• drought conditions are rare; but the ingress of North African air can bring spells of prolonged hot weather
• rain occurs throughout the year; but varies from place to place based on the relief (it chiefly runs in on cyclonic fronts and decreases to the east)
• depressions (cyclonic conditions, lows) are less common in summer than in winter, and generally bring warm but wet conditions
• anticyclones bring hot, sunny weather in summer and fog, snow, cold and still conditions in winter.

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Local weather processes and patterns

Low pressure, what is it?

If an area has pressure that is lower than its surroundings, then it is termed low pressure. Cyclones and depressions are low-pressure systems.

High pressure, what is it?

If an area has pressure that is greater than its surroundings, then it is termed a high-pressure area. Anticyclones are high-pressure systems.

Where are the high and low pressure belts found?

Causes of low pressure

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The low pressure synoptic chart for April over the UK

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Blocking anticyclone
This tends to be a large circulation that is no longer in the mid-latitudinal frontal belt. It effectively blocks the west to east passage of air, usually for several weeks. Within the high, typical and persistent anti-cyclonic conditions (for winter or summer, depending when the block occurs) prevail.