Some plants, especially the broccoli. Perks up afterward and it's developing
normally. It's mulched like crazy and the soil's nice & damp and of perfect
tilth. 80 degrees, sunny. Lots of rain in previous days.

I seem to recall reading many years ago that this drooping routine can be
due to some sort of mineral or nutrient imbalance. Anyone have any insight
about this?

Or, it's normal and never mind.