Solar Cycle 25 winds down: sunspot number falls to 45.7, last major flare in July

Solar activity is waning: the monthly average sunspot number fell from 60.3 in September to 45.7 in October, according to NOAA data cited by EarthSky. Cycle 25 peaked at 216 in August 2024.

The last confirmed X-class flare, the strongest category, was an X1.3 on July 4, 2026, NASA said. October's strongest flares were M-class, and one minor (G1) geomagnetic storm was recorded on October 21.

But be careful

Storms are still possible in the declining phase: around October 10 a series of coronal mass ejections triggered an unexpectedly strong geomagnetic storm, with auroras over Europe. Such storms can disrupt satellites, GPS and power grids.