It will last for five turns if created using Snow Warning (Generation VI onward) or Hail, or eight, if created by a Pokémon holding an Icy Rock. If created using Snow Warning (prior to Generation VI) or encountered in the overworld, it will last until replaced.
Snow falls slowly to the ground. Only found in Snowpoint City in Generation IV. In Generation V, it is referred to as "Snowy" by the gate's bulletin and is found on many days during winter in all places snow falls. In Generation VI, it is occasionally found in Dendemille Town and Anistar City, and sometimes falls outside Frost Cavern in the day after rescuing Abomasnow. No battles take place outside any buildings in Snowpoint City, so it is unclear if any weather is assumed in battle in Generation IV. In Generation V, however, light snow does not cause hail in battle, while in Generation VI, it does.
Precipitate falls more quickly and heavily, falling diagonally from one of the top corners of the screen, leaving the impression that it is being carried by strong winds, and sometimes appears to be mixed with hail. In Generation IV, it is found on Route 216, Acuity Lakefront, and at the summit of Mt. Silver. In Generation V, it is referred to as "Hail" by the gate's bulletin and is found on some days during the winter in Driftveil City, Cold StorageBW, Route 6, Mistralton City, Route 7, and Twist Mountain. In Generation VI, there is always a hailstorm on Route 17, as well as sometimes outside Frost Cavern, although only before rescuing Abomasnow.
Despite being referred to as "hail" in the games, the way it is depicted is more similar to ice pellets. While hail cannot occur during a snowstorm or in snowy areas in the real world, ice pellets can.