Observed long-term changes in extreme temperature and precipitation indices in Spain (1951-2020)

Climate extreme indices —-encompassing absolute values, percentile-based, and spell indices—- are analyzed over Spain during 1951-2020 using daily precipitation (PR), maximum and minimum temperatures (TX and TN) from the AEMET high-resolution dataset. The indices focus on the frequency, intensity, and duration of extremes. A general warming trend is detected in absolute values and in a longer persistence of warm spells. While the changes are clearer in TN- than in TX-based frequency indices, their sign and magnitude depend on the season and percentile. The upward (downward) trends in warm (cold) nights are usually larger than in warm (cold) days. A drying signal is detected on total precipitation and spell-indices in central and southern Spain during summertime. Isolated extremes increase during autumn, indicating a possible modification of precipitation regimes. This work contributes to disentangling the spatio-temporal variability and recent trends of extremes in Spain, with tailored climate information for adaptation measures.