New 22" WSM Body has arrived. HELP!

I always measure my cooking temp at the grate. But when I measure it at the top of the dome near the factory thermometer it is way off. Maybe I just got a bad one but I have read others on here say the same thing. It was the first thing I checked when I fired it up.

Just curious, what's the temp outside?

I always count out 12 briquettes to light this always gets me in the 250-275* range