Humidity is a factor in thermal comfort. Meaning, high or low relative humidity can be uncomfortable. According to the Environmental Protection Agency, indoor relative humidity should be kept below 60%. Ideally, between 30% and 50%.

Maintaining the right humidity levels ensures that you have a healthier and more comfortable environment. You sleep better, you get sick less, and you just feel healthier overall. According to the Environmental Protection Agency (EPA), indoor humidity levels should be kept between 30% to 50%, with the sweet spot being 45%.

As temperatures drop to a range of 25°F to 50°F, a humidity level of up to 40% is ideal for optimal comfort. In colder weather, with temperatures between 0°F and 25°F, maintaining a humidity level between 30% and 40% helps prevent dry air discomfort.

Most people feel comfortable when the relative humidity is between 30 and 50%. However, what is most important is not the absolute humidity, but rather the temperature-humidity index (THI). The THI is a measure of how hot it feels when the effects of both temperature and humidity are combined.