ukcp-probabilistic-extremes-report-september-2020.pdf
, Brown et al. (2014) estimated a 20-year return level of 35.7°C for summer TXx in London, for 1961-90. Such rare daily events can occur either during short spells of hot weather associated with particular synoptic conditions (e.g. during 2018, McCarthy et al., 2019), or during an extended heatwave