Therapeutic and Relaxing Nature Sounds 

Soothing, relaxing, calming sounds of rain and thunderstorm to give you a restful and a good night sleep. 
Studies have shown that the natural sounds of rain can create a relaxing environment and it also promotes deeper sleep. 
A study found that exposure to nature sounds — including rain — reduced stress levels, and improved sleep quality.
On the other hand, thunderstorms help transfer the negative charges back to earth (lightning is generally negatively charged). Without thunderstorms and lightning, the earth-atmosphere electrical balance would disappear in five minutes! And if this balance wasn't maintained, we aren't really sure what would happen.