Gilan has a humid subtropical climate with by a large margin the heaviest rainfall in Iran reaching as high as 1,900 millimeters in the southwestern coast and generally around 1,400 millimeters. Rasht, the capital of the province, is known internationally as the “City of Silver Rains”. Rainfall is heaviest between September and December because the onshore winds from the Siberian High are strongest, but it occurs throughout the year though least abundantly from April to July. Humidity is very high because of the marshy character of the coastal plains and can reach 90 percent in summer for wet bulb temperatures of over 26 °C . The Alborz range provides further diversity to the land in addition to the Caspian coasts.The coastline is cooler and attracts large numbers of domestic and international tourists. Large parts of the province are mountainous, green and forested. The coastal plain along the Caspian Sea is similar to that of Mazandaran and mainly used for rice paddies. Due to successive cultivation and selection of rice by farmers.
Mazandaran province: The western and central plains up to the northern foothills of Alborz Mountain Range, experience the mild climate of the Caspian region.There is a moderate mountainous climate with long cold winters and short mild summers. In this region, snow covers parts of the province even up to the middle of the warm season. In fact, snow can be observed even in the warmest months of the year which lends a touch of beauty.