Data shown on mapsIsoline maps

Different maps can show geographical data in different ways. Chloropleth maps use shades of colour to show variations in data over wide areas. Isoline maps join places that share a value. Dot maps can show distribution or density. Proportional symbol maps show different values with changing sizes of circles or other symbols.

Part ofGeographyGeography skills

Isoline maps

Isoline maps show lines that join up areas or values that are equal.

In this example, air pressure is shown using the isolines. The areas of equal pressure are joined using a line, which helps people to see the position of high and low pressure systems.

Generally, when the number is below 1000 we would consider that low pressure, and when over 1000 it would be high pressure.

Isoline map showing the UK and North West Europe. A key below it explains the isobar and weather front symbols that appear on the map.
Synoptic chart for the UK and part of Europe

Question

UK map labelling Glasgow, Belfast, Manchester, Liverpool, Birmingham, Bristol, Cardiff, Plymouth, London, Leeds, York, Newcastle upon Tyne, Edinburgh, Dundee and Aberdeen
UK cities

Compare the map above to the isoline map at the top of the page.

  1. Name a city in Scotland experiencing low pressure.
  2. Name a city in England experiencing low pressure.
  3. What type of pressure is Cardiff experiencing?
  4. What type of pressure is Belfast experiencing?

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Dot maps
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Choropleth maps

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