What kind of seed? Unfortunately it's too late for germination this year. It's all about average soil temperature, length of sunlight. You're south of me a fair bit, but typically the last couple weeks of August in Iowa is when I get the prep work done, kill off the weeds, or level the ground or whatever it is I'm doing, sow seed, water every day. September is grow time. I'll have mowed a couple times at least by mid October, before any hard freeze comes, and if things go well it's difficult to even tell there was any bare spot there. Sometimes it takes a while for the lighter color of newer turf to darken, but you get the idea. Every year is of course a bit different, but late August, early September is germination time. The idea basically is to avoid the 90°+ dry heat, once the brutal heat subsides then get busy, the trend is your friend - cooler temps and increased precipitation, soil temps in the 60° range or thereabouts.

thanks for the response. it's a fine fescue blend. I know this should have been done earlier - like i said, I was annoyed the lawn guy did it this late. he said in early August he wanted to do it soon so I bought the seed and then he didn't bother getting around to it until this week. I guess that makes it dormant / frost seeding... I just don't know if I should be watering during this time. I don't want to rot out the seed or make in try to germinate only to get killed off (it's supposed to get near 60 next week but I don't expect that to last long). I just don't know if I'm wasting my time or possibly even making things worse by watering when it's this cold. I'm in Columbia MO specifically if that helps any.

when I've read about frost seeding, they talk about the freeze and thaw cycles but don't say if you should water. maybe because they expect snow to be on the ground (which would melt and water the seed)

The deed is done. The aim for the frequent light watering is to keep the seed moist. At this time of year morning dew keeps my grass wet until the afternoon. There is little evaporation, usually a fair amount of rain anyway. The seed can probably be kept moist without much watering. See what happens. You may get germination. You could seed in late winter/early spring if this seed does not come up.

so, if I'm understanding your response Becky, l shouldn't water any more? and maybe hope I get germination but not until spring?

Plenty of nice weather in Missouri as far as i can tell. Do it!

I have crappy soil - like clay I think. I've been watering so that each area only gets 10 minutes (once a day) and it still puddles. well, 20 mins with a sprinkler that goes back and forth so I figure each half only gets half of the 20 minutes. Anyway, I guess I can cut that in half. And maybe only every other day (or when it looks visibly dry). Thanks for the answer. I just hope the seed doesn't die. it was kind of expensive and it would be a shame for it to go to waste because my lawn guy waited too long - I mostly let him do it because he was going to aerate beforehand. probably try overseeding again myself in spring.