At which phase of the solar cycle does the Sun's magnetic field typically reverse?

At which phase of the solar cycle does the Sun's magnetic field typically reverse? Solar maximum is the answer.

The Sun follows an approximately 11-year sunspot cycle, moving from solar minimum to solar maximum and back again. Around the activity peak, its polar magnetic fields weaken, pass through near-zero strength, and re-emerge with opposite polarity.

This reversal is produced by the Sun's magnetic dynamo, driven by flows of electrically conducting plasma inside the star. Decaying sunspot fields are transported toward the poles, helping replace the old polar field with one of opposite polarity. The reversal does not mean every local magnetic loop flips simultaneously; the Sun's surface remains magnetically complex.

A common mix-up is confusing the 11-year sunspot cycle with the roughly 22-year Hale cycle. After two 11-year cycles, the Sun's magnetic field returns to its original polarity. Solar maximum is also associated with more sunspots, flares, and coronal mass ejections, although the exact timing of the reversal can vary from cycle to cycle.