I am trying to understand when I should address spatial auto-correlation.
Let's say that I have a number of weather stations in the mountains and an equal number of weather stations by the sea. I want to measure if there is a statistically significant difference in annual rainfall between these two groups.
I am not trying to build any predictive model. I just want to perform a t-test to compare the two situations.
The observations within the two groups are not independent:
Nonetheless, all stations in a groups are not identical copies. Each one of them measures unique rainfall values due to very local topography, variability in wind patterns, etc.
Is spatial auto-correlation an issue in this situation?