The mosquito-borne viral diseases of dengue and Zika are one of the fastest growing public health threats in the tropics. Mathematical models that describe how these diseases are spread are powerful tools for understanding their global emergence and their impact on affected populations. In this talk I will show how spatial models fit to epidemiological data have allowed us to better understand ZIKV outbreaks, improve our understanding of the burden they impose in endemic areas and help us better plan for future spread.