It's going to be raining today but I did want to spend some time outside. What are some activities I can do outside in the rain?
1. Hike in the rain - with it raining outside, don't let that deter you from going on a hike. You'll simply need to get some rain boots and put on a rain jacket. It is highly recommended to pick an easy trail that way, you won't have to worry about slipping. 
2. Play with your feet - I'm sure when you were a child you may have splashed around in some puddles, as it was really fun. This simple activity can be extremely comforting as you walk around barefoot in the grass and let the mud squish in between your toes.
3. Makes some art - staying on the topic of mud, it could be a really good idea to make some temporary artwork. You can take a lot of mud and sculpt it into whatever you want or simply use the mud as a means to paint something. The good thing about this is that it's all temporary and will wash away, so you won't have to worry about any cleanup.
4. Mindfulness - if you feel like reducing your stress and don't feel like being too active outside in the rain, this would be perfect for you. All you need to do is find a comfortable place to sit and listen to the rain as your mind wanders and you come in tune with your surroundings.