RT Journal Article T1 Synoptic conditions leading to extremely high temperatures in Madrid A1 García Herrera, Ricardo Francisco A1 Prieto, Luis A1 Díaz, J. A1 Hernández Martín, Emiliano A1 Teso, T. del AB Extremely hot days (EHD) in Madrid have been analysed to determine the synoptic patterns that produce EHDs during the period of 1955-1998. An EHD is defined as a day with maximum temperature higher than 36.5°C, a value which is the threshold for the intense effects on mortatility and it coincides with the 95 percentile of the series. Two different situations have been detected as being responsible for an EHD occurrence, one more dynamical, produced by southern fluxes, and another associated with a stagnation situation over Iberia of a longer duration. Both account for 92% of the total number of days, thus providing an efficient classification framework. A circulation index has been derived to characterise and forecast an EHD occurrence. This paper shows that EHD occur in Madrid during short duration events, and no long heat waves, like those recorded in other cities, are present. Additionally, no clear pattern can be detected in the EHD frequency; the occurrence is tied to changes in the summer location of the Azores high. PB European Geophysical Society SN 0992-7689 YR 2002 FD 2002-02 LK https://hdl.handle.net/20.500.14352/59842 UL https://hdl.handle.net/20.500.14352/59842 LA eng NO © European Geophysical Society 2002. Topical Editor J.-P. Duvel thanks I. Durre and J. Coiffier for their help in evaluating this paper. DS Docta Complutense RD 6 jul 2025