A review of solar cycle prediction methods and their performance is given, including early forecasts for Cycle 25. The review focuses on those aspects of the solar cycle prediction problem that have a bearing on dynamo theory. The scope of the review is further restricted to the issue of predicting the amplitude (and optionally the epoch) of an upcoming solar maximum no later than right after the start of the given cycle. Prediction methods form three main groups. Precursor methods rely on the value of some measure of solar activity or magnetism at a specified time to predict the amplitude of the following solar maximum. The choice of a good precursor often implies considerable physical insight: indeed, it has become increasingly clear that the transition from purely empirical precursors to model-based methods is continuous. Model-based approaches can be further divided into two groups: predictions based on surface flux transport models and on consistent dynamo models. The implicit assumption of precursor methods is that each numbered solar cycle is a consistent unit in itself, while solar activity seems to consist of a series of much less tightly intercorrelated individual cycles. Extrapolation methods, in contrast, are based on the premise that the physical process giving rise to the sunspot number record is statistically homogeneous, i.e., the mathematical regularities underlying its variations are the same at any point of time, and therefore it lends itself to analysis and forecasting by time series methods. In their overall performance during the course of the last few solar cycles, precursor methods have clearly been superior to extrapolation methods. One method that has yielded predictions consistently in the right range during the past few solar cycles is the polar field precursor. Nevertheless, some extrapolation methods may still be worth further study. Model based forecasts are quickly coming into their own, and, despite not having a long proven record, their predictions are received with increasing confidence by the community.

对太阳周期预测方法及其性能进行了回顾，包括第 25 周期的早期预测。该回顾重点关注太阳周期预测问题中与发电机理论有关的那些方面。审查的范围进一步限于预测不晚于给定周期开始后即将到来的太阳活动极大期的幅度（以及可选的历元）的问题。预测方法分为三大类。前体方法依赖于特定时间太阳活动或磁力的某种测量值来预测随后的太阳极大值的振幅。选择一个好的前体通常意味着相当多的物理洞察力：事实上，越来越清楚的是，从纯粹的经验前体到基于模型的方法的转变是连续的。基于模型的方法可以进一步分为两类：基于表面通量输运模型的预测和基于一致发电机模型的预测。先驱方法的隐含假设是，每个编号的太阳周期本身都是一个一致的单位，而太阳活动似乎由一系列相互关联性不那么紧密的单个周期组成。相比之下，外推法的前提是产生太阳黑子数记录的物理过程在统计上是同质的，即其变化背后的数学规律在任何时间点都是相同的，因此它适合于分析并通过时间序列方法进行预测。在过去几个太阳周期的整体表现中，前体方法明显优于外推法。 在过去的几个太阳周期中，一种能够始终在正确范围内产生预测的方法是极地前兆。尽管如此，一些外推方法可能仍然值得进一步研究。基于模型的预测正在迅速发挥作用，尽管没有长期经过验证的记录，但社区对他们的预测越来越有信心。