A lower granular temperature zone near the orifice in silos was found by speckle visibility spectroscopy technology.Surprisingly,the values of granular temperature in this area are inversely proportional to the mass discharge rate (MDR).This finding that links the macroscopic MDR with mesoscopic dynamics temperature of the particle system,is obtained by looking at the effect that different outlet sizes of silos on MDR and granular temperature field.Apart from evidencing the relevance of a parameter that has been traditionally overlooked in silos,this relationship supposes a benchmark with which to explore the influence of small orifice sizes on MDR.Among these,we found that the frequency of intermittent clogging and their dependence on the size of the outlet.