A big problem of altitude setting.

[GG5678]

My location is in Fisherman's Wharf, San Farancisco. I've searched altitude of this place in google, it shows the altitude is 2.
But every time the defalut will return to around -35 automatically when I open my PokeFarmer, is it the real figure? Should I change this default to 2 every time before I start botting?

Thanks in advance!