Definition: Snow grains: Precipitation of very small opaque white particles of ice that falls from a cloud. These particles are fairly flat or elongated. Their diameter is generally less than 1 mm.
Although frozen and occurring when the temperature is between approximately 0 °C and –10 °C, the other properties of this precipitation correspond to drizzle. When the grains hit hard ground, they do not bounce.
Snow grains fall mostly from Stratus or from fog, and never in the form of a shower. Except in the mountains, snow grains usually fall in small quantities.