Map of the variation in the number of tone categories in local Chinese dialects in the core Chinese-speaking area, reflecting fieldwork conducted between December 2002 and December 2006. It is customary to treat syllables with stop codas as separate tone categories. For example, Cantonese has a 3-way tonal distinction in stop-final syllables and a 6-way distinction in other syllables, yielding a total of 9 categories.
Own work

Dialect data from Cao Zhiyun (ed.) (2008) Linguistic Atlas of Chinese Dialects (汉语方言地图集), vol. 1 Phonetics, Map 001.
Voronoi polygons generated using QGIS
Coastline and lakes from Natural Earth 1:10m Physical Vectors
Boundaries from Natural Earth 1:10m Cultural Vectors
Conversion to SVG using svgis
Kanguole