Time for my monthly update on the Sun’s sunspot activity has it proceeds through its eleven-year sunspot cycle. NOAA has released its update of its monthly graph showing the number of sunspots on the Sun’s Earth-facing hemisphere, and I have posted it below, annotated with further details to provide a larger context.

In December sunspot activity increased slightly for the second month in a row, but only by a little bit. The number of sunspots for the month was still significantly below the highs seen in the summer, and continue to suggest that the Sun has already entered solar maximum (two years early), and like the previous two solar maximums in 2001 and 2013, will be double peaked.


The graph above has been modified to show the predictions of the solar science community for the previous solar maximum. The green curves show the community’s two original predictions from April 2007 for the previous maximum, with half the scientists predicting a very strong maximum and half predicting a weak one. The blue curve is their revised May 2009 prediction. The red curve is the new prediction, first posted by NOAA in April 2020.

Though it remains too early even now to trust any predictions, the Sun will have to increase its sunspot activity quickly and significantly in the coming months, recovering quickly from the drop the past few months, to avoid a double-peaked maximum.

More important, if we are in maximum now, its strength is definitely not what the entire solar science community predicted. The red curve is the prediction of a panel of NOAA scientists, and it predicted the maximum would occur in 2025 with a monthly sunspot high of 115. The high counts that occurred in the summer of 2023 were about 160, 40% higher. Under any statistical system that error margin means that NOAA prediction was the equivalent of throwing a dart at a wall, blindly.

A dissenting group of scientists in turn had predicted a high in 2025 of 233. If we are already in a double-peaked maximum, this prediction is just as wrong, 31% higher than the real peak, which also indicates the prediction was a guess.

Obviously it is still early. The Sun could still be ramping up to a big solar maximum, but even this second group of dissenting solar scientists have admitted it is unlikely it will match their first prediction, stating in April 2023 they expected the high now to be 185. Bully for them. A shoeshine boy in Grand Central Station could have made that prediction, now that we are in maximum.

The scientists are guessing because they really do not understand the fundamental reasons why the Sun undergoes this solar cycle, related to the ebb and flow of its magnetic field. We know it happens, but we don’t know why. Nor do we know why it changes from cycle to cycle, and even undergoes long periods of low activity, called grand minimums, lasting as long as a hundred years.

The significance of this fundamental ignorance relates directly to the Earth’s climate. There is a great deal of climate data that suggests an active Sun causes the climate to warm, while an inactive Sun results in a major cooling. For example, during the last grand minimum in the 1600s, the Earth experienced what scientists call the Little Ice age, with some years having no summers resulting in crop failures and famines.

Knowing why the Sun’s sunspot activity changes will help us better predict any changes in the Earth’s climate. Right now all climate models fail to include the Sun properly in their calculations, essentially because none of them understand that specific component. Until they do, every climate model prediction is suspect.

In other words, in every way you can imagine, the science is not settled.