Significant changes in the regional climate of the Aegean during 1961–2002

Significant changes in the regional climate of coastal and island stations in and bordering the Aegean during 1961–2002 are identified. Here we start with a very large number of parameters describing the surface temperature climate measured at 9 Greek island and coastal stations, and highlight those parameters which show regionally significant trends. Statistical significance of trends is assessed over multiple sliding time‐windows of data. For each parameter and each time‐window, a regional summary is produced using two quantities: the statistical significance of the trend in the regionally averaged parameter, and the number of stations which individually show significant trends in that parameter. The relationship between these two quantities provides a simple way of highlighting those climate parameters for which the region shows a trend, which is spatially relatively homogeneous, and those for which the region may need to be divided into sub‐regions. Some very detailed characteristics of trends in daily surface temperatures are summarized in a concise way. Notably, the established cooling during the 1960s is shown to be especially strong for November and also December. Some trends were also shown to be significant only in terms of temperatures of unseasonably warm or cool days. For example, cooling in May temperatures in the late 70s/early 80s occurred most clearly for the low‐temperature range–appearing as a decrease in the temperature reached by unseasonably cold days. This behaviour was inhomogeneous across the region, with significant cooling at only a subset of the stations. Such results could be used by subsequent analysis to focus on particular parts of the data, rather than using averaging to reduce the data. Copyright © 2008 Royal Meteorological Society