It is the beginning of the month, so it is time for my monthly sunspot update. According to NOAA’s June update of its monthly graph of the sunspot activity on the Earth-facing hemisphere, the amount of sunspots in May surprised us once again by increasing upward, though the totals continue to be below prediction.

That graph is below, annotated with extra information by me to illustrate the larger scientific context.


The graph above has been modified to show the predictions of the solar science community for both the previous solar maximum as well as the ongoing 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. At the beginning of April 2025 NOAA’s panel of solar scientists added the purple/magenta curve line, predicting that solar maximum was over, and that the ramp down to minimum had begun.

The green dot marks the activity in May, a jump from the previous activity in April.

I must say it again: The Sun’s behavior throughout the past two solar cycles has never matched the predictions. While for most of this solar cycle, the ramp up to solar maximum was much faster and more active than predicted, the ramp down has generally been faster but less active than predicted.

And while the predictions for the last cycle (the blue and green curves) said it would be more active than it was, the prediction for the ongoing cycle (the red curve) said it would less active than it was.

This increased activity in May is not yet significant. Overall the Sun does appear to be continuing its ramp down to solar minimum. Nonetheless, there still remains the slim possibility that this increase heralds the coming of a second peak in solar activity, making this sunspot maximum a double-peaked one similar to the last. At present this cycle appears to be unusually short, so a second peak would do a lot to make it comparable to the past cycles in the last 250 years.

We won’t know however for probably another six months.

We also don’t know if the fundamental internal structural changes of solar activity just under the Sun’s surface, detected by recent research looking at data from the last forty years, has been contributing to the present activity and the unexpected weak maximums for the past two cycles. That research found that sunspot activity has been increasingly confined to the first 600 miles, a depth that barely scratches the surface considering the Sun’s large size.

Solar science continues to be a somewhat superficial science, based mostly on observations of phenomenon whose fundamental processes are simply not well understood.