About this map
ORNL LandScan data visualization.
What it shows
Oak Ridge National Laboratory produces LandScan, gridded estimates of population. ORNL has discontinued the daytime/nighttime product used in this visualization, so the most recent data is from 2021.
This map combines daytime and nighttime population estimates so that the difference between them can be visualized. Using this map, you can see how people cluster during the day, drawn into relatively small areas in high concentrations from broad catchment areas. The continental US can be divided into about 1.22 billion grid cells, each roughly 90 m across. Only 52.7 million of them are populated in the day or night. Between night and day, about 218 million people move from cell to cell. They leave about 42 million cells, each losing only about 5 people on average, and crowd into about 9 million cells. It is a cycle of extreme concentration and dispersal repeated daily throughout the country.
- Nighttime: people at home. This is close to what a census counts.
- Daytime: people at work, at school, shopping or other.
Drag the day/night slider and watch the columns grow and shrink. That movement is the daily concentration and dispersal of human activity.
Reading the columns
At the closest views, each column is a square about 90 m across. As you zoom out, those squares are merged together and averaged into larger blocks so that the columns stay fairly consistent at any scale.
Height shows how many people are estimated to be present per square kilometer. Heights are compressed as numbers increase to reduce the impact of extreme concentration.
Color also represents people per square kilometer:
Controls
- Night / Day: blends between daytime and nighttime estimates.
- Tilt and Rotation: change the viewing angle. Reset view faces north at a 50° tilt.
- Basemap: changes the map underneath.
- Columns and Column opacity: hide the columns, or make them see-through to read the map beneath.
- Aggregation: change how aggressively the columns are combined and averaged.
- Height and Height ∝ density: make the columns taller overall, and change how strongly the heights are compressed. A higher power means less compression.
Data and limitations
Population estimates come from LandScan USA 2021, produced by Oak Ridge National Laboratory. It models where people are from census counts, land use, buildings, jobs, schools and other sources. It's a rough estimate.
- Populations on tribal lands may be undercounted.
- Areas built or changed since about 2021 may be missing or out of date.
- The daytime estimate describes a typical weekday. It doesn't cover nights out, weekends or special events.
Credits
Population: LandScan USA 2021, Oak Ridge National Laboratory, licensed CC BY 4.0.
Basemaps: © CARTO, © OpenStreetMap contributors.
Built with MapLibre GL JS, deck.gl and PMTiles.