It is more than just measuring sunspots and magnetic fields. We are interested in as many aspects of the sun as possible. There are so many unknown physical mechanisms and processes involved that we need to do as much study as possible. We don’t even understand why the corona is hotter than the sun’s surface. There are structures, such as convection cells, and features, such as waves generated when flare material comes crashing back to the sun’s surface, and a large number of other areas of active study.
https://solarscience.msfc.nasa.gov/

The sunspots are interesting because they have some historical context and value. They are also where a lot of action occurs.

We understand so little about the sun and we know so little about how it affects us and the space we live in.

https://wattsupwiththat.com/solar/

The page has links to present and past solar data. You might find a link to magnetic field data either there or at one of the links on that page.

Welcome to the discussion. Phill O is correct; we do not have this answer, but it is a long time. It is not that there are zero sunspots in one month, as we have had solar minimums many times in the past, this one being the 24th. It is an effect of long duration periods of low numbers of sunspots.

The Little Ice Age corresponds with a “grand minimum” of sunspots, in which sunspots were rarely observed for a century, and now that we have been coming out of the Little Ice Age for three or four centuries, the Earth’s temperature has been increasing at a fluctuating rate. This increase in temperature predates, by two or three centuries, our industrial revolution and the tremendous increase in CO2 production in the second 1/3 of the last century, which is usually blamed for the current increase in the Earth’s temperature.

So far, many climates have not returned to what they were before the Little Ice Age, suggesting that the Earth is still generally cooler than it was back then. Unfortunately, our objective temperature measurements of various locations on the Earth started only in the mid 1800s, so we don’t have good objective data on temperatures before then.

The conclusion is that sunspot activity does not affect temperatures on an annual time frame but on a centurial or millennial time frame.

As pointed out in another of Robert’s posts, the temperature records are being surreptitiously modified by many of those who are supposed to collect and guard them. This renders meaningless our records and throws doubts into past, present, and future climate science. Past science is based upon the previous — now non-existent — historical temperature data. Current science is being based upon the recent — also now non-existent — historical temperature data. Future science will be based upon the modified historical temperature data that has yet to be adequately explained as to why and how it was modified to its current values. Phill O’s use of the term fudged data is applicable. The objectivity of previous measurements has been destroyed. There is much doubt as to the objectivity of current measurements, too.
https://behindtheblack.com/behind-the-black/points-of-information/the-greatest-scientific-fraud-of-all-time-part-xxiii/#comments

Climate science has been turned into a cluster [bleep]. Thank God I did not choose to be a climate scientist, as my life’s work would now be worthless.

The use of sunspot numbers to determine historical correlations with temperature must be done with care. We have better instruments, now, and must make sure that we do not include sunspots that could not have been seen during the past “grand minimum” when we determine the next grand minimum. If we count spots that could not have been seen and counted by our scientist ancestors, then it is like comparing apples to oranges; both are fruit, just not compatible fruit.

As we gain more precision and accuracy in our data, we must take care to avoid corrupting our conclusions by incorrectly comparing current and future data with historical data. With care, both can be compared (both are fruit), but we are limited in our comparisons. As Phill O said, it is like fudging the data and drawing incorrect conclusions, either purposefully or accidentally.

The yesterday’s cycle 25 sun spots were very short lived, so monitoring once a day might not have seen such transients.

ZRegime

Time to market = season lag period applied to a longer term climatic change.
We do not know at this point.

The sun spot numbers form one index for monitoring the solar activity over time. Of course it is not optimal and better ways of monitoring are yet to be invented. The 107 cm band is a relatively new index. Others will come. Right now the sunspot index gives data for about 400 years. Any new index will require at least that time-frame before any thought of drawing conclusions can be had. Otherwise, we get into a situation like the ozone scam where we suddenly had technology to detect what was there before. A similar situation is now present for noctilucent clouds where these were first categorized recently and, of course, with new interest, many more sightings..

However, if we use the sun spot index, monitoring (or detection) protocols MUST be Exactly the same as when these were first documented. To change protocols mid stream is, in affect, fudging data.

I think they would have been able to see even small sun spots. Sunspots, have been recorded in detail since the mid-medieval period.

The Catholic church used solar moron to regulate its calendar. To that end they had many cathedrals built with camera obscura forming holes built into the roof.

Each day at noon these would project a a large image of the Sun on the floor, complete with the dark areas of sunspots. As sunspots migrate across the solar disk as the sun rotates, all sunspots would appear on every sliver of projected sun image.

Other cultures tracked then as well.

Insolation during a solar minimum may change by 0.1%, not much of a change. There is a slight spectral shift during a minimum which might contribute to some of the effects seen. But the answer is that we still don’t know enough one way or the other in regards to how the Sun’s various cycles affect the climate on Earth and the other planets in the solar system. It’s all guesswork at this point, but at least it’s Scientific Wild-Assed Guesswork (SWAG).

unfortunately, the relationship between sunspots and solar wind and cloudiness and temperature is considerably beyond our current understanding

Phill O asked, “Would astronomers then have missed them even if they could have seen them?”

Assuming you are referring to the 1600s, when the last grand minimum occurred, your question is an excellent one. I don’t know, but since the grand minimum began almost the moment Galileo discovered the telescope, astronomers then assumed that sunspots were rare events. They knew nothing of the solar cycle, and during the 1600s saw almost no sunspots.

Could they have seen the two next-cycle spots from this past month? Once again, I don’t know. I suspect probably not, but that is a guess.

I have read at least one paper that thinks we will be able to see sunspots throughout the next minimum, using our modern equipment. That paper predicted the spots would be faint and weak, but detectable.

To many questions at this point to draw any kind of conclusions IMO.