I put three DS18B20s on a wire along with three SHT30s on D1 mini shields, all in a cardboard box indoors, for a day.

My conclusion is that the DS18B20s are actually more accurate. My Fluke’s thermocouple also agreed with them.

The SHT30s all read several degrees higher, with the one that was at an angle reading a little lower than the others which were flat. When I turned them all on edge their temperatures converged a bit lower but still a bit high. I wonder if some of the spikes from their readings are just microcontroller activity.

I’m hoping to use the Tasmota TempOffset command to adjust.