Sand Stream summons a sandstorm in battle as soon as a Pokémon with Sand Stream enters the battle. Its effects almost are the same as Sandstorm's; the only difference is that instead of lasting for five turns, it lasts for the whole battle until a different weather condition replaces it. If a Pokémon with Sand Stream is sent out in the same turn as another Pokémon whose Ability causes a different weather condition, the slower Pokémon's Ability will override the faster Pokémon's Ability.
In Generation VI, the sandstorm will last only for five turns instead. This can be extended to eight turns if the Pokémon is holding a Smooth Rock.
In Super Mystery Dungeon, Sand Stream changes the weather to sandstorm upon entering a floor. Sandstorm lasts a certain number of turns (in multiples of 66) before clearing. After the weather has cleared, Sand Stream will again activate after waiting a certain number of turns (in multiples of 66).