I had to move some dwarf dahlias from their containers that they seemed to outgrow. It's been raining a lot the past few days so the soil in the new and old containers was already wet. Should I water the dahlias in or just let the soil dry out a bit first?

I always water fairly heavily for a few days if I move them, unless it's raining. They always seem appreciative and accept that this is their new home.

this time of year in NY I find my dahlias need to be watered nearly every day, and your conditions are way hotter than mine, it's barely broken 85 degrees up here. in the ground, full size blooming dahlias.. i don't think it's possible to overwater.

As for watering your dwarf dahlias, I think it's best to let the soil dry out a bit before watering them again. With all the rain you've been getting, they should have plenty of moisture to hold them over for a bit.