Regional projections for the number of days per year with the NOAA Heat Index exceeding 41°C for different scenarios, time horizons and global warming levels. 41°C corresponds to conditions that the US National Weather Service classifies into the category of ‘Danger’ (Blazejczyk et al., 2012). The bar plots show projections from CMIP6 (darkest colours), CMIP5 (medium colours) and CORDEX (lightest colours) ensembles, for RCP8.5/SSP5-8.5 (red) and RCP2.6/SSP1-2.6 (blue), for the mid-term (2041–2060), long term (2081–2100) and the recent past (grey, 1995–2014). Results for global warming levels (defined relative to the pre-industrial period 1850–1900) are shown in purple for 1.5°C, yellow for 2°C and brown for 4°C. The median (dots) and the 10th–90th percentile range of model ensemble values across each model ensemble and each time period are shown for the regional mean over land areas for the AR6 WGI Reference Regions (defined in Chapter 1). Bias adjustment is applied. The CORDEX ensemble is missing in regions that are not fully covered by the CORDEX domain (EEU, ESB, RAR, RFE and WSB). See Technical Annex VI for details of indices and bias adjustment. Further details on data sources and processing are available in the chapter data table (Table 12.SM.1).