WNV mosquito cases and their spatial-temporal clusters in years 2002–2007. Figure 2A is for year 2002, and 2B for year 2003; Figure 2C is for year 2004, and 2D for year 2005; Figure 2E is for year 2006, and 2F for 2007. In each graph, X-axis presents latitude; Y-axis shows longitude; Z-axis shows WNV mosquito cases; Expected cases are shown in Z-axis for spatial-temporal clusters. Each cluster shows time period of cluster (month/day), cluster radius. p-value for rejecting the null hypothesis of no clustering is 0.001 for each cluster.