Space weather refers to the variable conditions (solar flares, geomagnetic storms, the Kp-index, Schumann resonance, aurora, and related meteoropathy topics) in the space environment surrounding Earth — driven primarily by the Sun's activity — that can affect technology in orbit and on the ground, and potentially human health. It spans timescales from hours (a single flare) to years (a full solar cycle), and it's studied, monitored, and forecast by government agencies the same way terrestrial weather is, with watches, warnings, and public alert scales.