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UKCP09 Climate change projections

UKCP09 provides probabilistic climate change projections, which are the result of an innovative modelling approach that explores the uncertainty in the Met Office Hadley Centre climate model. The projections also include the results of other IPCC climate models and are constrained by a wide range of observations of past climate.

In detail

The UKCP09 probabilistic projections provide projections of climate change, and absolute future climate for:  

  • Monthly, seasonal and annual climate averages.
  • Individual 25km grid squares and for certain pre-defined aggregated areas.
  • Seven 30 year time periods: 2010-2039, 2020-2049, 2030-2059, 2040-2069, 2050-2079, 2060-2089, 2070-2099.
  • Three emissions scenarios: Low (IPCC SRES: B1), Medium (IPCC SRES: A1B) and High (IPCC SRES: A1FI).

Projections of climate change are based on change relative to a 1961-1990 Baseline.

Find out more


  • An overview of how probabilistic projections are created and presented in UKCP09 is described in 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 how to interpret the UKCP09 probabilistic projections.
  • Some Worked examples were developed prior to the launch of UKCP09 that used dummy outputs to examine how the UKCP09 probabilistic projections might be used. The worked examples should not be interpreted as a best practice method for using UKCP09, but as one way of using the outputs.