An XY heat map uses a grid of colored cells to represent values at the intersection of two categorical axes. Color intensity encodes magnitude, making it easy to spot patterns, peaks, and gaps in matrix-style data.
Best Times to Spot the ISS — Visibility Guide
Best for
- Revealing patterns in two-dimensional categorical data
- Showing activity or intensity over a grid (e.g., day vs hour)
- Identifying hotspots and cold spots in large matrices
Avoid when
- You need to read exact values — color perception is imprecise
- One axis is continuous — use a line or area chart
- The matrix is very large — consider aggregation or sampling
Alternatives: Choropleth Map