:Issued: 2026 Jan 01 09:57 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 December 2025 : 124.0 (one hundred and twenty-four point zero) Maximum : 186 on 3, 4 // Minimum : 50 on 19 Provisional daily International Sunspot Numbers for December 2025 : 1..156 6..171 11..121 16.. 78 21.. 68 26..126 31..143 2..180 7..161 12.. 98 17.. 82 22.. 82 27..150 3..186 8..164 13.. 86 18.. 67 23..110 28..162 4..186 9..155 14.. 71 19.. 50 24..131 29..145 5..176 10..132 15.. 77 20.. 59 25..128 30..143 61 cooperating stations on January 1, 10 UT Predictions of the monthly smoothed Sunspot Number using the last provisional value, calculated for June 2025 : 124.7 (+-5%) SM CM SM CM SM CM 2025 Jul 120 121 2026 Jan 113 116 2026 Jul 103 110 Aug 115 118 Feb 112 116 Aug 100 107 Sep 119 115 Mar 110 116 Sep 98 104 Oct 117 114 Apr 108 115 Oct 96 102 Nov 116 114 May 107 114 Nov 93 99 Dec 115 116 Jun 105 112 Dec 90 95 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 #--------------------------------------------------------------------# # World Data Center SILSO # # Sunspot Index and Long-term Solar Observations # # Royal Observatory of Belgium # # Tel.: ../32/(0)2/373 02 33 Fax : ../32/(0)2/374 98 22 # # Please do not reply directly to this message # # For more information, contact: silso.info@oma.be # # or visit first our Web site at: http://www.sidc.be/silso # # To unsubscribe, visit http://sidc.be/registration/unsub.php # #--------------------------------------------------------------------# ---------------------------------------------------------------------- | Legal notices: | | - Intellectual Property Rights: | | http://www.astro.oma.be/common/internet/en/data-policy-en.pdf | | - Liability Disclaimer: | | http://www.astro.oma.be/common/internet/en/disclaimer-en.pdf | | - Use and processing of your personal information: | | http://www.astro.oma.be/common/internet/en/privacy-policy-en.pdf | ----------------------------------------------------------------------