I recently tracked a compost heap from start to reaching thermal equilibrium. Partway through we started another one, and one of the sensors was allocated to tracking ambient. While a single data point isn’t conclusive, it was interesting to see the week 37 (12-18 Sept 2016) second breath of this heap after the second turn coincided with a week of particularly warm weather. This points to a potential ambient sensitivity and it being worth tracking ambient in future and perhaps insulating the heap more in the later stages.
I will keep the technology of remote temperature sensing here, because I’d imagine horticulturalists aren’t that into electronics 😉