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Cumulative Distribution Function (CDF) plots

Cumulative Distribution Function (CDF) plots are a type of graph that you can use to visualise the UKCP09 probabilistic climate projections. A CDF plot shows the probability associated with change being less than a certain amount.

For example, you could use a CDF plot to show the probability associated with temperature in the UK changing by less than 2˚C by the 2050s under a high emissions scenario.

In detail

CDF plots show probabilistic climate projections or probabilistic climate change projections for a particular climate variable, spatial locationtime periodtemporal averageemissions scenario and probability level.

A CDF plot might be useful for those who want to know the probability of climate change being less than a specified threshold, for example where an impact of interest is known to start to occur.

Some prepared CDF plots are used to illustrate the UKCP09 reports. Customised CDF plots can be creating by building a request in the UKCP09 User Interface.

Find out more


  • CDF plots are explained in more detail in the Reports & guidance section. More information about Cumulative Distribution Functions is given in Annex 4.1 of the UKCP09 Climate change projections report.
  • An overview of how probabilistic projections are created and presented in UKCP09 is described in Box 3 of the UKCP09 Briefing report.
  • More details are provided in Chapter 3 of the UKCP09 Climate Change Projections report, including an overview of the methodology and a discussion about the interpretation of UKCP09 probabilistic projections.
  • A discussion of sources of uncertainty in the UKCP09 probabilistic projections is available in Annex 2.4 of the Climate change projections report.
  • The UKCP09 User Interface Manual