What controls the weather over the UK, and how do depressions and anticyclones bring their typical conditions?
The effect of latitude, altitude, relief, aspect and distance from the sea on local weather; the five air masses that affect the UK; and the weather associated with depressions and anticyclones, read from a synoptic chart.
An SQA National 5 Geography answer on weather, covering how latitude, altitude, relief, aspect and distance from the sea affect local weather, the five air masses that reach the UK, and the contrasting weather of depressions and anticyclones read from a synoptic chart.
Reviewed by: AI editorial process; not yet individually human-reviewed
Have a quick question? Jump to the Q&A page
Jump to a section
What this dot point is asking
The SQA wants you to explain the factors that control local weather across the UK (latitude, altitude, relief, aspect and distance from the sea), name and describe the five air masses that reach Britain, and describe and explain the contrasting weather brought by depressions and anticyclones, including reading the symbols on a synoptic (weather) chart.
What controls local weather
Five factors shape the weather of any place in the UK. You should be able to use each to explain why two places differ.
The sea's effect is sometimes called a maritime influence, and the inland effect a continental influence. The UK's mild, wet climate comes from being a small island in the path of south-westerly winds off the warm Atlantic.
The five air masses
An air mass is a large body of air that takes on the temperature and moisture of the area it forms over. Five reach the UK:
- Tropical Maritime - from the warm Atlantic to the south-west: warm and wet, the most common, bringing cloud and rain.
- Tropical Continental - from North Africa and southern Europe to the south: warm and dry, bringing heatwaves in summer.
- Polar Maritime - from the cold North Atlantic to the north-west: cold and wet, bringing showers.
- Polar Continental - from Eastern Europe and Russia to the east: cold and dry, bringing freezing weather in winter.
- Arctic Maritime - from the Arctic to the north: very cold and wet, bringing snow.
Depressions: low pressure
A depression is an area of low pressure where warm and cold air meet along fronts. Depressions move in off the Atlantic from the west and bring the UK's typical wet, windy weather.
- The warm front arrives first: cloud thickens and lowers, giving a long spell of steady rain; temperature rises.
- The warm sector that follows is mild and cloudy with drizzle.
- The cold front brings a short, heavy burst of rain, gusty winds and a fall in temperature.
- Behind the cold front there are bright spells with scattered showers.
Isobars around a depression are close together, so winds are strong and blow anticlockwise around the low.
Anticyclones: high pressure
An anticyclone is an area of high pressure that brings calm, settled, dry weather because sinking air stops cloud forming. The weather it brings depends on the season:
- Summer anticyclone - clear skies, hot sunny days, light winds; can lead to heatwaves and, at night, dew or early mist.
- Winter anticyclone - clear skies let heat escape at night, giving frost and fog; days are cold but bright. Winds are light and blow clockwise around the high.
Examples in context
Example 1. A wet day in the west of Scotland. South-westerly winds bring Tropical Maritime air off the Atlantic. As it meets the western Highlands the air is forced to rise (relief), cools and gives heavy rain, which is why places like Fort William are among the wettest in the UK.
Example 2. A frosty November morning in the Cairngorms. A winter anticyclone brings clear skies and light winds. Heat escapes overnight, and the high altitude makes it colder still, so a hard frost forms by dawn even though the day is bright and dry.
Try this
Q1. State the type of pressure system that brings dry, settled weather. [1 mark]
- Cue. An anticyclone (high pressure).
Q2. Name the air mass that brings warm, wet weather to the UK from the south-west. [1 mark]
- Cue. Tropical Maritime.
Exam-style practice questions
Practice questions written in the style of SQA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
SQA N5 style4 marksDescribe, in detail, the weather conditions normally associated with a depression as it passes over the UK.Show worked answer →
A 4-mark Describe question rewards four developed weather statements, so plan a point for each stage of the depression passing over.
As the warm front arrives, cloud thickens and lowers and there is a long spell of steady rain (nimbostratus cloud), with the wind increasing and the temperature beginning to rise.
In the warm sector between the two fronts the rain eases to drizzle or stops, skies stay cloudy and grey, and temperatures are mild.
As the cold front passes there is a short, heavy burst of rain, sometimes with thunder, the wind becomes gusty and often changes direction, and the pressure starts to rise.
Behind the cold front the air clears to bright spells with scattered heavy showers, and the temperature drops. Markers reward detail such as named cloud, the change in temperature, wind and pressure, not just "it rains".
SQA N5 style4 marksGive reasons for the differences in temperature between coastal and inland places in the UK in winter.Show worked answer →
"Give reasons" means each mark needs a cause, not just a statement, so link every point back to why.
The sea heats up and cools down more slowly than the land, so in winter the sea is warmer than the land. This warmth is carried onto coastal areas, keeping them milder than inland places.
The prevailing south-westerly winds blow in off the relatively warm Atlantic, so coastal places in the west are warmed further, while inland places are cut off from this maritime influence.
Inland places have no nearby sea to moderate temperature, so they cool down quickly on clear winter nights and can be several degrees colder, with a greater risk of frost.
Markers reward the cause each time (slow cooling of the sea, the warming effect of onshore winds, the lack of a moderating sea inland), so a bare statement of the difference with no reason scores nothing.
Related dot points
- The formation of features in glaciated upland landscapes - corrie, arete, pyramidal peak, U-shaped valley, hanging valley, truncated spur and ribbon lake - by the processes of glacial erosion and deposition.
An SQA National 5 Geography answer on glaciated upland landscapes, explaining how glacial erosion and deposition form corries, aretes, pyramidal peaks, U-shaped valleys, hanging valleys, truncated spurs and ribbon lakes, with named UK examples.
- The formation of coastal features of erosion - headlands and bays, cliffs, caves, arches and stacks - and of deposition - beaches, spits and sand bars - by wave action and longshore drift.
An SQA National 5 Geography answer on coastal landscapes, explaining how wave erosion forms headlands, bays, cliffs, caves, arches and stacks, and how deposition and longshore drift form beaches, spits and sand bars, with named UK examples.
- The formation of river features - V-shaped valley, waterfall, meander, ox-bow lake and levee - by the processes of river erosion, transport and deposition along the long profile.
An SQA National 5 Geography answer on river landscapes, explaining how river erosion, transport and deposition form V-shaped valleys, waterfalls, meanders, ox-bow lakes and levees along a river's course, with named examples.
- Land uses in glaciated upland, coastal, river and limestone landscapes - farming, forestry, industry, recreation and tourism, water storage and renewable energy - and the conflicts that arise between them and the solutions adopted to manage them.
An SQA National 5 Geography answer on land use and management, covering the land uses found in glaciated upland, coastal, river and limestone landscapes, the conflicts that arise between users, and the solutions used to manage them, with a National Park example.
- Ordnance Survey map skills - four and six-figure grid references, scale and distance, contours and gradient, recognising landscape features, and using map evidence to judge land use suitability - as examined in the question paper map item.
An SQA National 5 Geography answer on Ordnance Survey map skills, covering four and six-figure grid references, working out scale and distance, reading contours and gradient, recognising physical and human features, and using map evidence to judge land use, as tested in the question paper map item.
Sources & how we know this
- National 5 Geography Course Specification (C833 75) — SQA (2025)
- National 5 Geography - Course overview and resources — SQA (2025)