Rain, sleet, or snow that contains a high concentration of acids is called acid precipitation.

This is a broader term that encompasses:

* Acid rain: Specifically refers to rainwater with a pH lower than 5.6.

* Acid snow: Snow with a pH lower than 5.6.

* Acid sleet: Sleet with a pH lower than 5.6.

The acidity in these forms of precipitation is mainly caused by the presence of sulfuric and nitric acids, which are produced by the burning of fossil fuels and other industrial processes.