A little further west and north, zone 6. A little further east and south, zone 7. Basically the line between zones runs through the area. You should actually be paying attention to your own microclimate, and judge for yourself in your yard. There are very minor differences between 6b and 7a.

I read in Birds & Blooms magazine that the USDA was working on a heat zone maps (like the hardiness zone map we use already) so we can check mean cold & heat. Anyone know if it has been done? The magazine was from 2001. Surely would be a help for gardeners, tho like you said, microclimates can occur in zones (we have one in the N Shenandoah Valley).