Graphs of monthly SOI values and SOI Phases, 1899 - current
Please note: the daily SOI value published on 23 December 2016 was incorrect due to a data processing error. The corrected value was published on 3 January 2017. If you accessed our SOI data or SOI phase information between those dates we recommend you download a new copy to ensure you have the corrected information. We apologise for any inconvenience caused.
Most recent graph
PDF version of current graph (PDF, 17kB, last updated 16:46 20 Feb 2017)
Last updated: 28 June 2010