Recent trend in temperature evolution in Spanish mainland (1951-2010): From warming to hiatus

The most recent debate on global warming focuses on the hiatus in global temperature, for which several explanations have been proposed. On the other hand, spatial variability and nonlinearity in temperature evolution has been recognized as a key point in global change analyses. In this study, we analyse the evolution of the warming rate in the Spanish mainland using the MOTEDAS data set for the last 60 years (1951-2010). Our special emphasis is on the last decades to detect and identify a possible hiatus, and to determine the effects of daytime (T max ) and night-time (T min ) records at annual and seasonal scale on the hiatus. Moving windows running trend analyses were applied to calculate temperature trend and signi?cance for any temporal window from the beginning to the end of the series, ranging from 20 years to the whole series length (60 years) The results suggest that the warming rate in the Spanish mainland reached a maximum between 1970 and 1990, followed by a decrease in intensity in both T max and T min until the present. Furthermore, the decrease in the warming rate in T max has been higher than in T min for the last three decades; therefore, recent annual warming rates appears to depend more on T min than on T max . Signi?cant trends disappear from the middle of the 1980s at any temporal window length in both T max and T min at annual and seasonal scales except in spring T min . Some differences among seasons are evident and, during the last few decades, the highest rates of warming are found in spring and summer, with T max and T min behaving in different ways. This study highlights how the warming rate is highly dependent on the length of the period analysed.