There are three wavy lines and a cross in the circle. What is this symbol?

In the weather forecast, the icon of three wavy lines on the bar is dense fog.

Weather forecast icons are international, especially some of the most basic forecast icons. China Meteorological Bureau has also specially produced weather graphic symbols to standardize dozens of forecast icons including sandstorms and freezing rain.

However, with the weather phenomenon becoming more and more complex and changeable, new symbols emerge one after another. In the standard weather graphic symbols of China, there are at least 13 kinds of light related to rain, some turn from moderate rain to heavy rain, and some turn from heavy rain to heavy rain, but they all look like water drops under a cloud.