Sun Goes Spotless for First Time Since February 24

On September 18 at 8:30 UTC, the side of the Sun facing Earth showed no numbered sunspot groups at all, according to imagery from NASA’s Solar Dynamics Observatory (SDO). The finding comes from EarthSky, a site that tracks solar activity daily and publishes summaries of the latest images. If no new numbered group appears before the day is out, this would mark the first spotless day since February 24, 2026, nearly seven months ago. The day has not been officially confirmed yet, since the final tally only comes once every observation across the full 24 hour window has been added up.

Spotless days work as a marker of where the Sun currently sits within its eleven year activity cycle. The current cycle, numbered 25, peaked in late 2024, and the number and strength of sunspots, solar flares and coronal mass ejections have been gradually declining ever since. Spotless days rarely happen near a cycle’s peak; their frequency climbs as the Sun approaches its next minimum, a phase that, judging by how this cycle has unfolded so far, could still be a few years off.

The absence of sunspots comes from a daily comparison of SDO images against the catalog of numbered active regions kept by the United States’ National Oceanic and Atmospheric Administration (NOAA). A region earns a number once it is developed enough to track, and loses that status as soon as the Sun’s rotation carries it to the far side or it breaks apart. Spaceweather.com, which tracks the same phenomenon independently, also reported the Sun as temporarily spotless on September 18, but its table for that same day still listed a sunspot number of 11, so the two sources do not agree on the exact moment. The mismatch most likely comes down to a region just crossing onto the far side of the solar disk, a borderline case the two sources count differently until it settles.

Solar activity has stayed very low over the past 24 hours. Just one B class flare, the weakest category tracked, was recorded, with a strength of B3.2 that peaked on September 17 at 12:16 UTC. It came from region AR4521, which has since rotated onto the Sun’s far side. No Earth directed coronal mass ejections were recorded in the same period. The forecast for the coming days stays just as modest: NOAA’s Space Weather Prediction Center gives a chance of isolated C class flares through September 19, while Belgium’s SIDC puts that probability at 15 percent and drops the odds of a stronger, M class flare to just 1 percent.

The geomagnetic forecast for September 18 calls for unsettled to active conditions, with a Kp index between 3 and 4, while September 19 and 20 should calm to quiet or unsettled, Kp between 0 and 3. There is no geomagnetic storm warning in effect at the moment, and if aurora were to show up at all, it would only be visible at high latitudes, far from Serbia. Solar wind speed stands at 411.5 kilometers per second, with a density of 3.4 protons per cubic centimeter, according to Spaceweather.com.

By the site’s year by year count, 2026 has logged three spotless days so far, about 1 percent of the days that have passed. Neither 2025 nor 2024, both close to the cycle’s peak, recorded a single one. By comparison, 2019, near the bottom of the previous minimum, had 281 spotless days, 77 percent of the calendar year, and 2009 came even closer to a full minimum with 260 spotless days. The gap between those figures shows how far the current cycle still is from its own bottom, despite its decline from the 2024 peak.

Spaceweather.com stresses that the pause is temporary and expects sunspots to return quickly, with new flares and possible aurora in the days and weeks ahead. A single spotless day, even once officially confirmed, does not prove that Cycle 25 has ended, nor does it rule out stronger flares and coronal mass ejections in the near future. It only shows that the Sun is currently in a low activity phase, in line with the broader decline since the 2024 peak, while the exact date of the next minimum remains unknown.