Bing found the following results
Humidity - Met Office
What is humidity? Why measure & what your levels mean
Humidity - Wikipedia
What is normal humidity in a house and how is it achieved?
What Is Humidity? | NOAA SciJinks – All About Weather
Humidity | Atmospheric Effects, Measurement & Control | Britannica
Why is humidity important? - Met Office
What is humidity and how can we measure it? - BBC Bitesize
All About Humidity - National Geographic Society
Humidity - National Geographic Society