Time to update the state of the Sun, as seen by satellite data (the last update was in July). The graph below, posted today by Physikalisch- Meteorologisches Observatorium Davos (PMOD), shows the variation in the Sun’s Total Solar Irradiance since 1978. I have added a blue horizontal line to show that even now, two years after the Sun reached the lowest point in its most recent solar minimum, it has still not brightened enough to equal the lowest point in the two previous minimums. (Note that if we included the minimum from 1976, the Sun would still be below that as well.)

Once again, the evidence is building that the Sun might be heading towards the weakest maximum seen to two centuries. And when that happened, things got very cold on Earth.