Interim report by the Centro Nacional de Epidemiología (ISCIII) on mortality in Spain due to the Covid-19 pandemic, 4 April 2020 (Spanish).
The excess mortality rate rose sharply on 17 March and fell just as sharply from 15 April onwards. The metropolitan pandemic cluster of Madrid was particularly affected. There, the excess mortality lasted from 10 March to 8 April and also significantly exceeded that of the particularly affected autonomous region of Catalonia.
The interim report can be downloaded from the ISCIII (Instituto de Salud Carlos III) website.