30 Day Map Challenge 2026 · Day 04 · Clusters

Utah wildfire starts by cause

Every known-cause start inside Utah, 1992–2024. Zoom in and the clusters split; tap one for its natural/people split.

Both Natural People Clusters Density Dots

Starts per 1,000 km² per year

3103080

Natural on top, people below, one log scale for both; pale where both are dense. Drawn live by the SDK’s heatmap with a 14 km kernel, the spread of the poster’s 5 km Gaussian. Rates are per year of the years selected.

37,882

starts shown

  • 22,377 natural
  • 15,505 people

Natural is the source’s category and is broader than lightning. 3,235 records with no recorded cause are left out. Starts outside Utah aren’t in the data, so clusters along the state line read low.

Data FPA FOD 7th ed. (USDA Forest Service) · UGRC Utah boundary

Made with ArcGIS Maps SDK for JavaScript 5.1 (cluster pie charts, heatmap, layer blending), Calcite · data prep in Python (GeoPandas)

Brian Busch brian-busch1 @brianjbusch buschbrian @brianbusch1