Unless its really hammering down, DLP is great in the rain.
Far less people around, easier to move about as less crowds and so on.
Ok so if its really really throwing it down then perhaps you'd do well to get out of the weather, but anything short of monsoon conditions we just press on.
(I grew up in a family where the motto was "Wet Programme: Dry Programme, with Mackintoshes")
Top tips for a wet day:
Lightweight pacamac things in your bag
HATS not umbrellas (please, not umbrellas, I loathe them with a passion)
Waterproof shoes whatever it looks like when you get dressed in the morning - we're big fans of walking boots
If weather warm but wet - shorts. Skin dries really quickly and jeans don't.
then you can happily go jumping through puddles and whatnot.