Cycle forecasts

12-month forecasts of the monthly sunspot number

  • Standard curves method (Waldmeier)
  • Combined method (Denkmayr - Cugnon)
  • McNish&Lincoln method
  • Optimization of base predictions using a Kalman filter

  • Standard method prediction (Kalman)
  • Combined method prediction (Kalman)
  • McNish & Lincoln method prediction (Kalman)
  • 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: )
    Royal Observatory of Belgium Av. Circulaire, 3 - B-1180 Brussels, Belgium