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CDF Data

Cumulative Distribution Function data (CDF data) is available to UKCP09 users through the User Interface .

Each set of CDF data is provided for a certain climate variable at a specific:  

The CDF data are used to create the Cumulative Distribution Function graphs. The data are available from the UKCP09 User Interface .

CDF data are available for:

  • Climate change projections for grid squares, administrative regions and river basin regions
  • Marine & coastal projections for sea level rise.

Probability in the CDF data

The CDF data provides values of future climate change for a range of variables. The values correspond to a set of probability levels, which show the probability of the climate changing by less (or greater) than the value shown. For more information on how probability works in UKCP09 please see the 'Probability in UKCP09' page.

The CDF data shows more probability levels than other UKCP09 products. The CDF data shows probability at 107 pre-defined probability levels. These are at: 0.1, 0.25, 0.5, 0.75, and 1%, then at 1% intervals to 99%, then 99.25, 99.5, 99.75 and 99.9%.


Example of a Cumulative Distribution Function (CDF) that is formed using CDF data.

The probability levels 1-9% and 91-99% are less robust and should be used with caution. Probability levels of less than 1% and above 99% should not be used.

For more information see section 3.2.12 of the Climate Change Projections Report, in the Reports & guidance section.

More information on CDF data

More information about how to use the CDF data can be found on the 'CDF data in detail' page.

Need more help?

For questions and queries about UKCP09 please see our Help section.