They mean 98%-100% relative humidity. 100% relative humidity is the maximum amount of water that the air can hold at a given temperature and pressure as vapour. Once you get to 100% then you can evaporate any more water / was will start condensing out of the air (especially if the temperature drops)
They mean 98%-100% relative humidity. 100% relative humidity is the maximum amount of water that the air can hold at a given temperature and pressure as vapour. Once you get to 100% then you can evaporate any more water / was will start condensing out of the air (especially if the temperature drops)