Precipitation is an important climatic factor that reflects particular complexities. The statistical distribution
of total precipitation of a location may vary with time. Due to the arid and semiarid climatic conditions
of Iran, knowledge of the precipitation amount and variation is an important issue. Therefore in this
study the characteristics and trend of precipitation in 7 rain gauging stations in the Golestan province is
investigated during the 31-year period of 1974-2004. The linear regression and Mann-Kendall trend analysis
methods were used. The results indicated that at 5 % level, significant increasing trends have been
observed in the annual precipitation of the Tamar, Tangrah, and Gonbad stations. Increasing trend has been
found in the autumn precipitation in all stations, but it was significant only at the Tamar station at 5% level.
Precipitation in winter and spring did not show a significant and homogenous trend across all stations.
While the summer precipitation shows an increasing and homogenous trend across all stations. However
it is significant at 5% level only for the Gonbad, Tamar, and Cheshmeh khan stations. The maximum daily
precipitation of the Rabat Gharebil and Galikesh stations shows decreasing trend which is significant for
the latter at 5% level. But it shows increasing trend in the other stations from which the Tamar and Tangrah
stations have significant trends at 1% level. In case of number of days with rainfall events, all stations
showed an increasing trend which is significant at 1% level except for the Tamar and Cheshmeh khan stations.