It's easy to get demotivated to go outdoors when it has been so wet. Clients always dread the wet sessions but then tell me that they are the most fun.
I've said it before, embrace the weather-dont let mud and puddles put you off. Instead, try attacking them- on a bike, in old trainers or just a pair if wellies, get out there and play like a child. The slippery surface and the cold works the body harder therefore burning more calories.
When you're done a nice hot bath gets soon makes you feel civilised again-until next time!