Newbie Direct Grilling

Hi All,

I was wondering about estimating heat when direct grilling.
I preheat my Weber Q 220 to 500 (indicted by the thermometer) on the hood.

But when I cook second batch of meat . I put my hand about 5 inches from the surface to estimate the heat ( about 2 seconds for 500+ heat). But the thermometer still says something luke 300 or 400.. since the heat from the air has escaped already.

Is this accurate measure or should I rely on the thermometer. I figure the thermometer is more accurate measure of heat of the air inside the hood not of the grill surface.

Thanks

try putting digital thermometer probe in the grill to check the thermometer on the grill but don't have a fire to hot most digital thermometers get damaged at 500*

Thanks for the tip.
Just for curiosity sake , I ordered a grill surface thermometer from Outset.