Each file can be downloaded by clicking on the grey button corresponding to the chosen format. All files are in ASCII text and can be opened in any text editor. CSV files allow direct import in various applications, like spreadsheets.
Data Credits: The Sunspot Number data can be freely downloaded. However, we request that proper credit to the WDC-SILSO is explicitely included in any publication using our data (paper article or book, on-line Web content, etc.), e.g.: "Source: WDC-SILSO, Royal Observatory of Belgium, Brussels".
For additonal information, contact Frédéric Clette (E_mail: Frederic.Clette@oma.be ) Royal Observatory of Belgium Av. Circulaire, 3 - B-1180 Brussels, Belgium