Weather Words: Virga

Have you ever looked to the sky, or even from an airplane, and seen streaks of rain falling from a cloud but not reaching the ground? That’s called virga. It happens when raindrops or ice crystals start to fall but evaporate before they touch the surface. This creates streaks or wisps beneath the cloud that look like the sky is “raining in the air.”

Virga usually forms when the air below the cloud is very dry. As the precipitation falls, it encounters this dry air and evaporates quickly. This process cools the air as well. In deserts and dry regions, virga is a common sight, creating dramatic streaks of moisture that never reach the surface.

Even though the rain doesn’t reach the ground, virga is more than just a visual effect. It can influence local weather, including wind patterns, temperature, and even aid in the development of new clouds. Pilots especially watch for virga, because the cooling and downdrafts it creates can make the air turbulent. Virga can also show up on weather radar, appearing as rain, yet never reaching the ground.

While this weather phenomenon may seem subtle, it’s rather striking if you spot it in the sky.

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.