Table S5.

RMSE of each model output for every other scale in our analyses and RMSE standardized to the range of values in the response variables

Scale	RMSE			Standardized RMSE
	Bd	WNV	Lyme disease	Bd	WNV	Lyme disease
0.0625 degree2	0.4215	0.0746	0.0517	0.268	0.037	0.0005
0.25 degree2	0.4226	0.0744	0.0740	0.269	0.037	0.0007
1 degree2	0.4237	0.0745	0.0716	0.270	0.037	0.0007
4 degrees2	0.4260	0.0743	0.0718	0.271	0.037	0.0007

The RMSE represents the mean deviation between the observed and predicted values of the statistical model; thus smaller values indicate better overall fit of the model to the data. There were no scale-dependent patterns of RMSE across disease systems. RMSE units for Bd, arcsine-transformed prevalence and for WNV and Lyme disease are cases per 10,000 people. Standardized RMSE values are unitless proportions.