The seed itself can tolerate some freezing... what doesn't tolerate freezing very well are seedlings. If it germinated and then got a hard freeze, you might have to reseed.

However, if it hadn't germinated yet, it may be fine.

We use tall fescue up here where it actually does get cold... and we dormant seed it in the fall ... and it still grows in the spring.

My understanding is that I should keep the ground moist as the seeds work towards germination. How can I do that with such cold termps? Assuming my hose even works, won't the water cause the ground to ice over?

I know these sound like rookie questions, but I am not used to dealing with cold weather like this.

Thanks.

Right now you've got 2 bigger problems than the cold weather. First, while keeping the fescue seeds moist you're also keeping any weed seeds that may be on the ground moist too which will lead to a lawn full of weeds this summer.

Next problem is this summer, your new grass probably won't have a root system developed well enough to survive the heat so most of it will die.

Planting cool season grasses like tall fescue should be done in early September so the root system can grow deep enough to make it through the summer.

I looked at your temps its not going to be that cold. The air temperature is not the same as the soil temperature. The soil temps should be fine.

Seeding in the fall is preferred, but spring is the next best alternative. One can't always wait an entire growing season to seed, sometimes you need to put something down in the spring to get something growing. You can always overseed again in the fall.

Rest assured, I will be overseeding in the fall as well. My issue is that I had some trees that became too large last year and overshadowed portions of my lawn, which turned it into a dust bowl. I recognize some of it will die this summer, but I had to do something now or my yard would look horrible.