I notice that that after updating to Home Assistant version 0.34.0, the humidity reported from Nest website versus the one from Home Assistant is slightly off. i.e. Nest website would show 48% humidity, but Home Assistant shows 50% humidity.
I found out that the value of humidity only goes in 5% interval. (e.g. 40%, 45%, 50%).
Prior to version 0.34.0, the value of humidity would match exactly the same as what Nest website reported (e.g. 41%, 46%, 49%)