Monthly Ri Report

:Issued: 2026 Aug 01 08:16 UTC
:Product: documentation at http://www.sidc.be/products/ri 
#-------------------------------------------------------------#
# MONTHLY TABLE OF THE INTERNATIONAL TOTAL SUNSPOT NUMBER     #
# AND 12-MONTH PREDICTIONS from the World Data Center SILSO   #
#-------------------------------------------------------------#

Provisional International monthly mean Sunspot Number for
July 2026 : 78.1 (seventy-eight point one)

Maximum : 132 on 1 // Minimum : 25 on 18

Provisional daily International Sunspot Numbers for July 2026 : 

      1..132    6.. 65   11.. 71   16.. 47   21.. 87   26..100   31..118
      2..107    7.. 58   12.. 61   17.. 34   22.. 81   27..104
      3..102    8.. 75   13.. 39   18.. 25   23.. 90   28..100
      4.. 89    9.. 72   14.. 34   19.. 45   24.. 99   29..106
      5.. 89   10.. 71   15.. 26   20.. 74   25.. 95   30..125

69 cooperating stations on August 1, 08 UT

Predictions of the monthly smoothed Sunspot Number using the last
provisional value, calculated for January 2026 : 104.2 (+-5%)

            SM    CM                 SM    CM                 SM    CM     

2026 Feb    99   102     2026 Aug    81    96     2027 Feb    65    88
     Mar    95   103          Sep    79    95          Mar    62    85
     Apr    89   102          Oct    76    95          Apr    60    82
     May    87   101          Nov    73    93          May    57    80
     Jun    85    99          Dec    70    92          Jun    55    78
     Jul    83    97     2027 Jan    67    90          Jul    53    76

SM : SIDC classical method : based on an interpolation of Waldmeier's
standard curves; the estimated error ranges from 7% (first month) to
35% (last month)
CM : Combined method : the combined method is a regression technique
coupling a dynamo-based estimator with Waldmeier's idea of standard
curves, due to K. Denkmayr.
ref. : K. Denkmayr, P. Cugnon, 1997 : "About Sunspot Number Medium-Term
Predictions", in "Solar-Terrestrial Prediction Workshop V", eds.
G. Heckman et al., Hiraiso Solar Terrestrial Research Center, Japan, 103



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