The present study explores the spatial variability of the continentality, oceanity and aridity indices in Turkey. Climatic indices are diagnostic tools used to describe climatic conditions and the state of a climate system. In this study, four indices were calculated using the climatic data from 229 meteorological stations in Turkey. The nature of the indices expresses general climatic features such as continentality, marine influences and aridity. The climatic indices used here are the Johansson Continentality (JC) Index, the Kerner Oceanity Index (KOI), the De Martonne Aridity Index (I_DM) and the Pinna Combinative (PV) Index. Furthermore, aridity characteristics in Turkey have been examined using the two separate periods (1960–1990 and 1991–2006). To assess the temperature and precipitation patterns in Turkey, the climatic indices were calculated by using monthly temperature and precipitation for the period 1960–2006. According to the results of the KOI, marine climates characteristics were dominant in the Black Sea region than in its Aegean and Mediterranean region. The JC index is used for the climatic classification between continental and oceanic climates. The continental effect was found across 25% of the country. The maximum continentality with a score of 71.5 has been found in the eastern Anatolia. Furthermore, semi‐dry areas were increasing in the 1991–2006 period compared to 1960–1990. A significant correlation was found between the values of the JC index and the KOI. The JC index gives reasonable results for Turkey. The continental effect was found across 25% of the country. This analysis may be of benefit for the explanation of landscape characteristics and the rational utilization of water resources, agriculture and energy scenarios for the region in many areas of Turkey. Copyright © 2010 Royal Meteorological Society

Tourism activities are highly dependent on climatological conditions. The climatological suitability of tourism destinations is investigated by using a Tourism Climate Index (TCI) that is frequently used by researchers. The TCI varies between 0 and 100 and is created by using temperature, relative humidity, sunshine duration, wind and precipitation data. For TCI, 100 is for ideal and 0 is for extremely unfavorable conditions for tourism. In this study, the meteorological data covering the period of 1981–2020 for 98 stations is used to calculate the TCI of each station for all seasons and months. The Mann-Kendall trend test is used for TCI behavior of the entire country and Sen Innovative Trend Analysis method is used for four famous tourism destinations. For summer, coastal regions have smaller TCI values than inland regions due to the high amount of relative humidity. Most stations have TCI values in the “Very Good” category or better. In spring and autumn, the TCI values fall into the “Acceptable” category or better. The winter is the season with smallest TCI values. For summer, 54 of 98 stations have a decreasing trend at different levels of significance and four of them have an increasing trend. In autumn, 30 stations have an increasing trend and two stations have a decreasing trend at standard levels of significance. Similarly, for spring, 20 stations have an increasing trend and one has a decreasing trend. During winter, 14 stations have an increasing trend while one has decreasing trend. The Sen Innovative Trend test shows an increasing trend on average for four famous tourism destinations during May–September months.