I asked my biologist bud who works with me pretty much the same thing as late June thru mid-August were BONE DRY here in west TN. He said if the drought persists you're probably better off to NOT water them and just let the seed sit until sufficient moisture causes germination. Now since you watered them at planting I would recommend you to water them at least weekly or the drought might kill whatever germinated!
Lastyear my seed sat in the ground 3 weeks before it recieved the first drop of rain. (I drag everything with large section of heavy, double fencing so cut grass/weeds and dirt did lightly cover the seed plus aid any moisture retention) I was worried about germination and the kale & turnips never came up very well but the wheat came up fine. Since mid-August we've been avg weekly 1/2-1"+ of rain so the soil is now ready for planting which I plan to do over the next couple of weeks. Hopefully the rains will continue!
HL