Provisional International monthly mean Sunspot Number for
May 2013 : 78.7 (seventy-eight point seven)


Maximum : 135 on 16 // Minimum : 33 on 31

Provisional daily International Sunspot Numbers for May 2013 : 

      1.. 93    6.. 71   11.. 88   16..135   21.. 74   26.. 63   31.. 33
      2.. 68    7.. 76   12.. 93   17..120   22.. 86   27.. 60
      3.. 64    8.. 80   13..100   18.. 87   23.. 71   28.. 51
      4.. 80    9.. 76   14..105   19.. 83   24.. 71   29.. 47
      5.. 72   10.. 82   15..113   20.. 73   25.. 77   30.. 48

72 cooperating stations on June 1, 09 UT

Predictions of the monthly smoothed Sunspot Number using the last
provisional value, calculated for November 2012 :  59.7 (+-5%)

            SM    CM                 SM    CM                 SM    CM     

2012 Dec    58    60     2013 Jun    53    75     2013 Dec    48    88
2013 Jan    57    63          Jul    52    78     2014 Jan    47    87
     Feb    57    66          Aug    51    81          Feb    46    86
     Mar    56    69          Sep    50    83          Mar    46    85
     Apr    55    70          Oct    50    86          Apr    45    84
     May    54    72          Nov    49    87          May    44    83

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