What is the freezing point of kosher salt?

Kosher salt is essentially the same as table salt, just with a larger crystal size. Therefore, the freezing point of kosher salt is the same as the freezing point of regular table salt, which is -21.1°C (-5.98°F).

It's important to note that this is the freezing point of a saturated salt solution, meaning the maximum amount of salt has been dissolved in water. The freezing point of a less concentrated salt solution will be higher.