Here in the city, given the urban heat sink, I'm pretty solidly in Z 7, further north, or in an unprotected spot, etc., would more likely be closer to Z 6. This area is pretty much on the border, so your mileage may vary. The "zip code zone finders" sometimes list me as Z 6b and sometimes as Z 7a. If there's a Z 7 plant you want, try it, as long as you won't be upset if it doesn't make it.

Some people overwinter figs and rosemary around here - but a really cold winter can set back or even kill either of those plants, even if planted in a protected spot.

i live in southwest PA and ive been in zone 7 and 6 around me, for sometime

I know this is a little late to the party, but here is the url to the 2012 USDA Plant Hardiness Zone Map. On the interactive version of the map, you can click down to about one-quarter mile scale.

Here is a link that might be useful: 2012 USDA Plant Hardiness Zone Map

I have Z7 surviving plants along the back of my house open to full sun facing southwest, a microclimate. Otherwise Z6 to 6B in the rest, depending...as CarrieB says.

I have Z7 surviving plants along the back of my house open to full sun facing southwest, a microclimate. Otherwise Z6 to 6B in the rest, depending...as CarrieB says.