Under dry conditions there is a tendency to want to wait to apply POST herbicides until weeds are actively growing. With the exception of clethodim products for grass control, I suggest that applications for broadleaf herbicides not be delayed. Weeds will keep on growing even when dry. Apply earlier in the day can help with control and minimizes crop injury. Grass control with clethodim will be poor when grass is drought stressed. Apply the highest rate if you feel like you cannot wait. Antagonism by broadleaf/sedge herbicides will be greater relative to clethodim when grass is drought stressed or large.