Birds! Let Nature Sing - Cloudy days make me happy.

Rain sound is very relaxing.

Most people believe that seasonal affective disorder (SAD) is triggered by winters or sunless, rainy days due to the lack of sunlight, but in some rare cases, people feel depressed on sunny days and cloudy, dull skies make them happy. The condition is known as reverse SAD.

"Rain produces a sound akin to white noise. The brain gets a tonic signal from white noise that decreases this need for sensory input, thus calming us down. Similarly, bright sun tends to keep us stimulated." ... Rain, wind, and other storm noises are like this.