Weather Words: Blood Rain

Watch: Surreal Scene As Beach Turns Red

Blood rain is a rare weather phenomenon where rain appears red or reddish-brown, creating a dramatic, almost surreal visual effect. The color doesn’t come from actual blood, but rather, fine particles in the air, like desert dust or sand, or by runoff from iron-oxide-rich or naturally red soil. When rain passes through these particles or washes over colored soil, the water can pick up the pigments and carry them to the ground, making the rain, and sometimes nearby rivers or puddles, appear red.

This phenomenon can happen in areas with mineral-rich or vividly colored soil. Heavy rainfall can wash iron-oxide-rich sand or soil into streams, rivers, or coastal areas, producing a “blood-like” appearance in the water. Similarly, airborne dust or sand carried high into the atmosphere can mix with raindrops and create a red-tinted shower.

While historically blood rain was often viewed as an omen, it is a natural and harmless event. It’s a striking example of how atmospheric conditions, rainfall and the makeup of the Earth’s surface can interact to produce rare and visually stunning effects.

Jennifer Gray is a weather and climate writer for weather.com. She has been covering some of the world's biggest weather and climate stories for the last two decades.