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We analyzed the daily sunspot-group data reported by the GreenwichPhotoheliographic Results (GPR) during the period 1874-1976 and DebrecenPhotoheliographic Data (DPD) during the period 1977-2017 and studiedNorth-South asymmetry in the maxima and minima of the Solar Cycles 12-24. Wederived the time series of the 13-month smoothed monthly mean correctedwhole-spot areas of the sunspot groups in the Sun's whole sphere (WSGA),northern hemisphere (NSGA), and southern hemisphere (SSGA). From these smoothedtime series we obtained the values of the maxima and minima, and thecorresponding epochs, of the WSGA, NSGA, and SSGA Cycles 12-24. We find thatthere exists a 44-66 years periodicity in the North-South asymmetry of theminimum. A long periodicity (130-140 years) may exist in the asymmetry of themaximum. A statistically significant correlation exists between the maximum ofSSGA Cycle n and the rise time of WSGA Cycle n + 2. A reasonably significantcorrelation also exists between the maximum of WSGA Cycle n and the declinetime of WSGA Cycle n + 2. These relations suggest that the solar dynamo carriesmemory over at least three solar cycles. Using these relations we obtained thevalues 11.7 + or - 0.15 years, 11.2 + or - 0.2 years, and 11.45 + or - 0.3years for the lengths of WSGA Cycles 24, 25, and 26, respectively, and hence,July 2020, October 2031, and March 2043 for the minimum epochs (start dates) ofWSGA Cycles 25, 26, and 27, respectively. We also obtained May 2025 and March2036 for the maximum epochs of WSGA Cycles 25 and 26, respectively. It seemsduring the late Maunder minimum sunspot activity was absent around the epochsof the maxima of the NSGA-cycles and the minima of the SSGA-cycles, and someactivity was present at the epochs of the maxima of some SSGA-cycles and theminima of some NSGA-cycles.

North--South Asymmetry in Solar Activity and Solar Cycle Prediction, IV: Prediction for Lengths of Upcoming Solar Cycles