I stay in when it rains, I earn enough on dry days.
I work in the rain, not for the money per se, it's because I like to choose when my days off are.
I plan my working month, and choose the days off I need when they suit me best.
If it's raining on a work day, the choice is to reschedule the day(s) off I need and what I plan to do on them or just crack on in the rain.
Usually, working in the rain is preferable to rearranging my schedule.