The ideal home humidity level for inside your house is between 50 and 60 percent. This measurement should be maintained all year round, in both the winter and summer. In extreme weather conditions, it is more difficult to maintain. For example, in the winter you are likely to have your central heating on, and maybe your fire as well, and both of these produce dry heat which will reduce the humidity level. To increase the humidity in your home when using central heating, purchase a humidifier. Alternatively, if you use a fire to heat your rooms, then position a bucket of water next to the fire, as a cheaper alternative.