Why is the humidity so high when there is no water in the incubator when I first turn it on?

The reason your humidity reading is higher when you first switch on your incubator even though they may not be any water in the incubator is because the incubator is cold.

Generally, colder temperatures result in higher humidity levels and higher temperatures result in both lower humidity levels and drier air - explaining why we add water into the incubator to increase the humidity level.

As your incubator begins to warm up and reach temperature, you will see the humidity level come down and ‘settle’. There is not magic number it will arrive at once the incubator has reached temperature, it will depend on if you have added water and the ambient conditions.

If the incubator is in a cold room or a room with a draught, it is likely that  without water the humidity will go quite low, as cold air will draw the moisture out of the incubator. The incubator needs to be in a room where the temperature is at least 18°C (average room temperature). If the incubator is in a room which is at the ideal temperature, then it will settle at around 30%-40%.

Ideally, we would suggest to run the incubator without any water until it has reached temperature and the humidity has settled and then add the water bit by bit. This also gives you the chance to see how much water you need to reach the desired level.