Skip to main content


The estimated international sunspot number (EISN) is a daily value obtained by a simple average over available sunspot counts from prompt stations in the SILSO network.
Time range: current month.
Data description: Daily estimation of the Sunspot Number

Nb Data = Total Number of observations received at SILSO
Nb Valid Data = Total number of observations taken into account for calculating the EISN
Current average = Current average of the Sunspot Number
EISN : Estimated International Sunspot Number.