I also know nothing about the limitations of the temperature sensors on smartphones (I don't even know of any phones that have temperature sensors). What I do

I also know nothing about the limitations of the temperature sensors on smartphones (I don't even know of any phones that have temperature sensors). What I do know is that whilst teasing signals out of noisy data is achievable when the data are unbiased, the possibility of biases makes it significantly harder, especially when you don't know what the biases might be. This can be a significant problem with all sorts of data that you might think were fairly good, including both in-situ and satellite measurements.