Sunspot update: Activity rises slightly in April
It is the start of the month, so it is of course time for my monthly report on sunspot activity, based on the update that NOAA posts each month to its own graph of sunspots activity. As I have done since the start of Behind the Black in 2010, I take that graph each month and annotate it with extra information to illustrate the larger scientific context.
Sunspot activity in April did nothing to tell us anything about the Sun’s future activity. It rose slightly, but not by enough to suggest that the prediction put forth last month by NOAA scientists that the ramp down to solar minimum has begun is wrong.

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.
The black dot with green dot in the center indicates the activity for April, slightly higher than that seen in March but still below the new prediction added to the graph by NOAA scientists in April 2025 and indicated by the purple/magenta curve line. They predict that solar maximum is over, and the ramp down to minimum has begun. The activity in April neither confirms nor counters this prediction.
As I noted last month, in the previous solar maximum the Sun started what appeared to be a ramp down to minimum, than burst out with a flare-up of sunspot activity, making the last maximum double-peaked. This remains a possibility now, and the activity in April did nothing to discount that possibility either.
One of the reasons I make a point of showing all the predictions by the solar science community is to illustrate how little they really know about the Sun’s sunspot cycle. They know it happens; They know it lasts approximately eleven years; They know it is linked to the Sun’s magnetic field and its flip in polarity every eleven years; They know the sunspots occur at locations where the Sun’s magnetic field lines travel through the Sun’s surface.
But do they know the reasons why this process occurs? No. There is no real understanding why the Sun’s magnetic field flips, nor the fundamental processes in the interior of the Sun that cause it. This is why these predictions are so unreliable. They are not based on the fundamentals. Instead, they try to extrapolate future events based on past performance, something that every stock broker in the world will tell is is a poor method for predicting anything.
The failure here of the solar scientist community provides us an explanation as to why the predictions of climate scientists are as unreliable. The Sun’s behavior, as mysterious and as complex as it is, is actually quite simple compared to the complexity and chaotic climate of the Earth. And considering that we know almost as little about the long term fluctuations in the Earth’s climate as we do of the Sun’s sunspot activity, it is not surprising that all climate models continue to fail in their predictions.
And one reason those climate models fail is that they underestimate the Sun’s influence on our climate, including the Sun’s own mysterious variations relating to this very sunspot cycle.
We know very little. And we should not let the little we know blind us to this fact.
Readers!
My annual February birthday fund-raising drive for Behind the Black is now over. Thank you to everyone who donated or subscribed. While not a record-setter, the donations were more than sufficient and slightly above average.
As I have said many times before, I can’t express what it means to me to get such support, especially as no one is required to pay anything to read my work. Thank you all again!
For those readers who like my work here at Behind the Black and haven't contributed so far, please consider donating or subscribing. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Every one of those 2020 conclusions has turned out right.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
It is the start of the month, so it is of course time for my monthly report on sunspot activity, based on the update that NOAA posts each month to its own graph of sunspots activity. As I have done since the start of Behind the Black in 2010, I take that graph each month and annotate it with extra information to illustrate the larger scientific context.
Sunspot activity in April did nothing to tell us anything about the Sun’s future activity. It rose slightly, but not by enough to suggest that the prediction put forth last month by NOAA scientists that the ramp down to solar minimum has begun is wrong.
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.
The black dot with green dot in the center indicates the activity for April, slightly higher than that seen in March but still below the new prediction added to the graph by NOAA scientists in April 2025 and indicated by the purple/magenta curve line. They predict that solar maximum is over, and the ramp down to minimum has begun. The activity in April neither confirms nor counters this prediction.
As I noted last month, in the previous solar maximum the Sun started what appeared to be a ramp down to minimum, than burst out with a flare-up of sunspot activity, making the last maximum double-peaked. This remains a possibility now, and the activity in April did nothing to discount that possibility either.
One of the reasons I make a point of showing all the predictions by the solar science community is to illustrate how little they really know about the Sun’s sunspot cycle. They know it happens; They know it lasts approximately eleven years; They know it is linked to the Sun’s magnetic field and its flip in polarity every eleven years; They know the sunspots occur at locations where the Sun’s magnetic field lines travel through the Sun’s surface.
But do they know the reasons why this process occurs? No. There is no real understanding why the Sun’s magnetic field flips, nor the fundamental processes in the interior of the Sun that cause it. This is why these predictions are so unreliable. They are not based on the fundamentals. Instead, they try to extrapolate future events based on past performance, something that every stock broker in the world will tell is is a poor method for predicting anything.
The failure here of the solar scientist community provides us an explanation as to why the predictions of climate scientists are as unreliable. The Sun’s behavior, as mysterious and as complex as it is, is actually quite simple compared to the complexity and chaotic climate of the Earth. And considering that we know almost as little about the long term fluctuations in the Earth’s climate as we do of the Sun’s sunspot activity, it is not surprising that all climate models continue to fail in their predictions.
And one reason those climate models fail is that they underestimate the Sun’s influence on our climate, including the Sun’s own mysterious variations relating to this very sunspot cycle.
We know very little. And we should not let the little we know blind us to this fact.
Readers!
My annual February birthday fund-raising drive for Behind the Black is now over. Thank you to everyone who donated or subscribed. While not a record-setter, the donations were more than sufficient and slightly above average.
As I have said many times before, I can’t express what it means to me to get such support, especially as no one is required to pay anything to read my work. Thank you all again!
For those readers who like my work here at Behind the Black and haven't contributed so far, please consider donating or subscribing. My analysis of space, politics, and culture, taken from the perspective of an historian, is almost always on the money and ahead of the game. For example, in 2020 I correctly predicted that the COVID panic was unnecessary, that the virus was apparently simply a variation of the flu, that masks were not simply pointless but if worn incorrectly were a health threat, that the lockdowns were a disaster and did nothing to stop the spread of COVID. Every one of those 2020 conclusions has turned out right.
Your help allows me to do this kind of intelligent analysis. I take no advertising or sponsors, so my reporting isn't influenced by donations by established space or drug companies. Instead, I rely entirely on donations and subscriptions from my readers, which gives me the freedom to write what I think, unencumbered by outside influences.
You can support me either by giving a one-time contribution or a regular subscription. There are four ways of doing so:
1. Zelle: This is the only internet method that charges no fees. All you have to do is use the Zelle link at your internet bank and give my name and email address (zimmerman at nasw dot org). What you donate is what I get.
2. Patreon: Go to my website there and pick one of five monthly subscription amounts, or by making a one-time donation.
3. A Paypal Donation or subscription:
4. Donate by check, payable to Robert Zimmerman and mailed to
Behind The Black
c/o Robert Zimmerman
P.O.Box 1262
Cortaro, AZ 85652
You can also support me by buying one of my books, as noted in the boxes interspersed throughout the webpage or shown in the menu above.
Some things just don’t add up sometimes.
https://www.msn.com/en-us/science/ecology/elon-musk-details-horrifying-reason-why-he-wants-to-colonize-mars-life-insurance-for-life/ar-AA1Eg3eP?ocid=BingNewsSerp
“So, eventually, all life on Earth will be destroyed by the sun. The sun is gradually expanding, and so we do at some point need to be a multi-planet civilization because Earth will be incinerated,”
You might IMO argue that you have a credible existential concern about a life destroying asteroid on the level of the Chicxulub strike and that is a reason to launch a colonize Mars effort. But not because the sun at a minimum of at least 1 billion years will reconfigure itself and engulf the earth and incinerate it and all life. Maybe a solar flare direct hit event? You might even in a stretch argue that the climate is going to collapse due to human activity?
Nah, Antarctica has increased its ice cover grew by 108 gigatons over the last 5 years. https://nypost.com/2025/05/05/science/antarctic-ice-has-made-a-surprising-rebound-in-mass-scientists-say/
Does Elon think that technology would not be developed in the next 100 years? 1000 years? 5 or 10 thousand years that would make getting to and colonizing Mars or anywhere else much easier? In 100 thousand years?
Sometimes Elon does not make sense to me.