Research is pursued worldwide that aims to determine if a particular observed extreme event has become more or less likely due to climate change. A recent paper (King et al 2015 Environ. Res. Lett.10 054002) uses two methods to quantify how much more likely a record hot year in Central England has become. One of the methods is based largely on climate modeling, the other on interpreting the observed record. This is an important step towards improving the reliability of event attribution results. Improved understanding and prediction of changes in extreme events is recognized as one of the 'grand challenges' in climate research.