Spatio-Temporal Distribution of Historical Extreme Winter Temperatures in England and Scotland — A Non-Stationary Extreme Value Analysis

<jats:p> Cold temperature extremes can have a detrimental effect on human health, public services and the economy of a country. From a public health services perspective, it is important to quantify the frequency of occurrence of extreme cold events and how this frequency changes over time in order to develop cost-effective anticipatory plans to reduce the potential impact of cold extremes on the exposed vulnerable population. Using non-stationary extreme-value analysis, the geographical and temporal distribution of cold temperature extremes over the last 160 years in several locations in England and Scotland was investigated. The temperature data were obtained from weather stations. It is then shown that the 5, 10, 50 and 100 year return levels of minimum winter temperature have increased throughout the 20th century. It was also shown that the probability of experiencing extreme cold temperatures has become very low in most locations particularly in years with a positive phase of the North Atlantic Oscillation (NAO) index. Finally, an estimate of the approximate financial risk to the UK economy of consecutive days of extreme cold temperatures is presented. </jats:p>