sentences:  The warm, humid climate of Chalus was formerly considered unhealthy, and the bulk of the population of Chalus, as of all other towns in this region, used to migrate in summer to the summer pastures on the slopes around Delir and in the Kelardasht basin, one of the most popular and longest-settled districts in the region.The people residing in Chalus speak Mazanderani language.People of Chalus speak Mazanderani language In the west of Chalus, the dialect of kalarestaqi 
   is spoken and in the east of Chalus, the dialect of Kojuri  .During the Pahlavi dynasty, a group of Langrud people migrated from Gilan to Chalus.