Heatwave datasets#
A heatwave is a prolonged period of abnormally hot weather. There are different approaches to define a heatwave. In general, a heatwave is determined using thresholds for air temperature and its persistency (minimum duration as a number of days). The most common definition of a heatwave is the occurrence of multiple consecutive days with the maximum air temperature over a certain threshold. In some methodologies thresholds are also defined for the minimum air temperature.
The source of the heatwave hazard is the EuroHEAT project. The EuroHEAT hazard data are based on the health-related EU-wide definition: For the summer period of June to August, heat waves were defined as days in which the maximum apparent temperature (Tappmax) exceeds the threshold (90th percentile of Tappmax for each month) and the minimum temperature (Tmin) exceeds its threshold (90th percentile of Tmin for each month) for at least two days. The apparent temperature is a measure of relative discomfort due to combined heat and high humidity, developed based on physiological studies on evaporative skin cooling. It can be calculated as a combination of air and dew point temperature.
The EuroHEAT datasets represent (maps below) the average seasonal number of the heatwave days in summer months for selected reference (1986-2010) or projection (2016-2045 and 2046-2075) period. Future climate projections are illustrated for two-time horizons 2016-2045 as a near future, and 2046-2075 as further future. Two representative concentration pathways have been selected: RCP 4.5 (a moderate-emissions scenario in which carbon emissions rise until the 2040s, and then begin to decline) and RCP 8.5 (a high-emissions scenario, in which emissions continue to rise throughout the end of the century). The climate change projected under RCP 8.5 will typically be more severe than under RCP 4.5.
This map shows exposure layers representing Buildings and Built-up density retrieved from Global Human Settlement Layer (GHSL). The map also shows national boundaries (NUTS regions - level 0), but also regions of lower levels up to second level of NUTS regions.
Tip
Use the map layer icon in the top-right corner of the map to select and compare different hazard map layers.