The lid thermometers are horribly inaccurate regardless of cooking method. Often times differing from grate temp by 50-100 degrees. I mean who cares what the temp is up in the lid? That’s not where the meat is.

I personally use a Weber iGrill 2. It has inputs for up to 4 probes. I always dedicate one to grate temperature. They even have an [ambient probe](www.amazon.com/dp/B01MCWS60B/ref=cm_sw_r_cp_api_i_HXQM4RDAKMQ8JGPY25B2) specifically designed for this purpose with a clip to hold it on the grate.

Even if you don’t want to go the whole wireless route I would still recommend something that reads the temperature at the grate where it matters. Otherwise you are totally flying blind.

Edit: I placed a link to Amazon for the ambient probe. Not sure why it’s not showing up. See below.

Weber iGrill Pro Ambient Probe https://www.amazon.com/dp/B01MCWS60B/ref=cm_sw_r_cp_api_i_HXQM4RDAKMQ8JGPY25B2