E.g.
If it rains tommorow, and if I don't have an umbrella, I will get wet.
Or
If it rains tommorow and if I don't have an umbrella, I will get wet.
Which of these two is correct from a punctuation perspective? I know that I don't actually need the second if here. But this is obviously a simplified example, so let's say that I wanted to use it. Would I have to put in that additional comma?