I'm with Allison, I think freezing temps are pretty much over. I plan to do annuals soon as time allows. A couple of days ago I bought a new bin for cups of tomatoes. (One of my old ones fell apart).
The thing is, after all these years of wintersowing, I accept the fact that late frosts can and do occur. I'm willing to cover the annuals for a few nights, or even move them into the garage overnight if necessary. This approach has served me well. Otherwise, I wouldn't be thinking of sowing them yet.
After today, our 15 day forecast is for days in the 60s-70s, lows 40s-50s. Even allowing a wide margin of error, that looks pretty good and extends to March 24.
Karen