If you use another temp gauge that can read at the grate level you'll find about a 35 °F difference so you need to have a reading up there of 260 °F -270 °F for good BBQing temp at the grate.
For me this means showing our patriotism by wearing red, white, and blue all day long while doing what American's do best — bbqing, throwing back a few beers, laying in the sun, and spending time with family.