Extended Abstract
Introduction
In recent years, the economic benefits of tourism has attracted attention of many countries that have maritime border. In this regard, Caspian Sea which located in the northern part of Iran, has special potential in the field of tourism and it can be seen a bright future in the field of tourism just with a holistic approach in this field. Meanwhile, climate is the most important factor in tourism development. General Specifications of Destination Weather and daily, monthly and seasonal changes, temperature, precipitation, humidity, radiation, wind and other elements of the climate are important information for tourism destinations so that the applicant can plan in terms of travel time, type of clothing and equipment required. Tourism climatology includes a variety of topics about two applied issues of climate and tourism which is linked to the principles of atmospheric science, and in particular the study of climate on the one hand, and tourism, recreation and leisure on the other. In general, the present study seeks to answer the following question: What are the most appropriate timeframe for the development of tourism on the southern shores of the Caspian Sea?
 
Materials & Methods
In this research, the southern margin of the Caspian Sea, including three provinces of Golestan, Mazandaran and Gilan, as areas adjacent to the sea, have been studied and analyzed. Accordingly, 15 cities of Mazandaran province, 4 cities of Golestan province and 9 cities of Gilan province are located on the southern margin of the Caspian Sea that they are analyzed in terms of tourism climate index. The present study has been done on the method of descriptive- analytical and with aims of identifying the most desirable periods of climatic conditions for the development of tourism. The required data is obtained by method of library through documents, journals and books. In this regard, the required climatic parameters were collected from 2010 to 2014 in a 5-year period. In order to determination the appropriate timeframe for tourism development has been used from the method of TCI (Tourism Climate Indicator).
 
Results & Discussion
Based on the collected data, the TCI was calculated for each of cities along the Caspian Sea with a description of its descriptive class in different months of the year. The analysis of TCI indicate that respectively June and July are the most desirable time in terms of climate for the presence of tourists on the coast and the Caspian Sea. So that of the 28 neighboring cities of the Caspian Sea in June, there are 6 cities with very good climatic conditions, 6 cities with good climatic conditions, 12 cities with acceptable climatic conditions and 4 cities with low favorable climate conditions. Also In July, there are 6 points with very good conditions, 4 points with good conditions, 15 points with acceptable conditions and 3 points with low favorable climate conditions. In the meantime, in terms of the desirability of the climatic conditions, after June and July, the months of September, August, April, March, October, January, May, February, November and December are located.
 
Conclusion
In this research, the climatic conditions of the southern margin of the Caspian Sea, as one of the most important criteria for the development of tourism, were investigated. The results indicate that the southern margins of the Caspian Sea, each within a given time period, can provide favorable climatic conditions in order to attract tourists to these beaches. Somehow that in most of the months of the year you can see the favorable climate conditions for tourism in the area adjacent to the sea. The results of TCI indicate that over the years it can be seen areas with desirable climatic conditions in the Caspian Sea which it can be provided growth and development of tourism in this area with planning in appropriate time and place. Desirability of climatic conditions in the four months and coincided with the beginning of summer vacation, is a special opportunity to promote tourism and benefit from its significant economic advantages. In this regard the months of June, July, August and September is the most desirable periods for planning to presence of tourists and delivery of services to them. Also the months of April, March, October, January, May, February, November and December due to desirability climatic conditions are the next priority. Of course this does not mean that in these months, tourism remains silent, but the ratings is only Desirability of climate in different months. In fact, in almost all months of the year can be seen a favorable climate for the tourism in the area neighboring the sea.