A rainy day gives you time to play as it brings things around you to a slower pace. Most people unless they have to, would rather stay inside when it it pouring with rain outside. So when you are inside it gives you time to connect to you. To play and have some fun and to truly learn to love the very being that you are.
Try getting out the paints or playing some games. Meditate listening to the rain and feel the inner you glowing with warmth as it feels snug and warm inside. Do some baking or cooking. Whatever it is that makes you truly smile. For it need not be a glum day when the rain