Why we love it

We love it when cartography makes sense of complicated data. This map delivers, showing thousands of tornados averaged over time and space to reveal seasonal and regional patterns. The legend uses color to denote month, and size to show tornado intensity. We see the timing of peak tornado activity through animation. The rings, color-coded by season, keep us fixed on the map instead of the legend. We learn that some places have year-round tornado risk, while others are limited to summer months. A looping animated GIF emphasize the fact that tornados occur as a cyclical, annual process.

Why it works

Animated data really makes this map work. It draws focus beyond individual circles to the aggregate effect of circles synchronizing, blooming, and changing in waves. Just as when we watch a flock of birds, we no longer see individual birds. We abstract them into a simpler, larger visual object—a flock. With animated maps, hundreds of disparate symbols become a single, organic shape that shows both location and rate of change. This map is a great example of how animation can clarify a complicated dataset and nuance our understanding of geographic processes playing out over space and time.

Important steps


Tips and tricks

John Nelson, map author

Related maps

If you liked this map, check out these other Maps We Love that explore similar topics.

Learn more about making maps in ArcGIS Online

Learn more