UK Solar System Data Centre
Copyright WDC for STP at RAL.
Daily values from 14th February 1947 to 1990 were measured near Ottawa, Canada and since 1990 have been measured at Penticton, Canada.
Definitive values for observed and adjusted daily values and monthly means are usually available a month at a time about 10 days after the end of the month.
Prompt observed values are available next day via reports from the Space Environment Centre, Boulder, USA.
Smoothed values can be calculated after 6 months.