A brief overview of data of automated temperature monitoring systems at the periphery of nuclearly hazardous clusters of fuel-containing materials (FCM NHC) and analytical materials regarding the study of its dynamics at various monitoring points before and after installation of New Safe Confinement (NSC) into its design position, is presented. The characterization of revealed dominant trends in temperature time characteristics underway in the observation period from 1991 to 2015 and the reasons influencing their formation at various distances from FCM NHC boundaries in room 305/2, are addressed. The importance of the work of an expert research system (ERS), which functionally supplemented the existing nuclear safety monitoring system (NSMS) of CHNPP "Shelter" Object (SO) installed instead of decommissioned information and measuring system (IMS "Finish") and other autonomous FCM monitoring systems, is highlighted. A critical analysis of the state of current temperature monitoring around the FCM clusters is provided, and a conclusion about the need to improve the existing monitoring network is made.