HeatLens is designed for computers. For the full map experience, open it on a laptop or desktop.
About HeatLens
HeatLens translates satellite imagery into a single readable score — so planners, advocates, and residents can see exactly which communities bear the heaviest heat burden and where cooling investments will have the greatest impact.
Free for cities, forever — and we connect them to the businesses and solutions that cool them down.
HeatLens is an open urban heat risk tool covering the United States. It reads three satellite-derived datasets, combines them into a weighted score of 0–100, and maps the result by county, city, and census tract — so that anyone, whether resident, journalist, planner, or policymaker, can see at a glance which communities carry the heaviest heat burden and what drives it.
Urban heat islands form where concrete, asphalt, and buildings trap heat that trees and soil would otherwise release. According to the EPA, daytime temperatures in cities run about 1–7°F higher than surrounding areas, and nighttime temperatures about 2–5°F higher. Heat is the leading cause of weather-related deaths in the U.S., according to the National Weather Service.
Each area receives a score from 0 (severe heat risk) to 100 (coolest). Three satellite-derived factors are normalized, weighted, and summed. Higher contributions from temperature and impervious surface push the score down; more tree canopy pushes it up.
Score = 100 − (0.40 × T + 0.35 × (100 − C) + 0.25 × I)
T = surface temperature scaled against a fixed national range — 72.4°F–128.4°F, the 1st–99th percentile of warm-season temperatures across all U.S. census tracts (0 = at/below 72.4°F, 100 = at/above 128.4°F) · C = tree canopy cover % · I = built-up surface %
Surface temperature carries the most weight because it’s the most direct satellite measure of heat. Tree canopy is next because shade and evaporation are the strongest cooling factors; in the Lansing study, canopy was most strongly linked to cooler neighborhoods. Impervious surface is weighted lowest because much of its heating effect already shows up in surface temperature, so weighting it heavily would double-count.
At a score of 18, Phoenix is the most intense urban heat island HeatLens has measured in the United States. The breakdown shows why: an average land surface temperature near 130°F and tree canopy of just ~4% — almost no shade against extreme heat. Notably, Phoenix isn't the most paved city on the map (impervious surface is ~35%); it tops the scale because HeatLens weighs actual surface temperature and canopy, not pavement alone. That's exactly the pattern the tool is built to surface.
HeatLens grew out of a gap in the research: major cities get studied, mapped, and funded, while the mid-sized and post-industrial towns where millions of people live are routinely overlooked. The Lansing case study behind HeatLens showed that the same heat dynamics shaping big metros are at work in these smaller cities too — they've simply never been measured. The vision is to close that gap: give any community, whatever its size or budget, the neighborhood-level heat intelligence that until now only major cities could access. Every place added is one more community that can see its risk and act on it.
National research has found that historically redlined neighborhoods run about 4.7°F hotter on average. But in the Lansing case study behind HeatLens, heat didn’t simply follow income: the coolest neighborhood studied was the lowest-income one, while older, denser areas with less tree canopy ran hotter. What drives exposure is the physical design of a place: its age, how much pavement it has, and how many trees are left. That’s why HeatLens measures the built environment directly.
Cities, researchers, advocates, and community organizations — whether you want deeper analysis, custom data exports, or to bring HeatLens into your own planning tools, we'd love to hear from you.
Each area is scored 0–100, where 100 is the least intense urban heat island and 0 is the most intense. Three satellite-derived factors combine to produce the score:
Scores are calculated for U.S. counties, states, cities, and census tracts using publicly available federal data, and are always shown as a number alongside color so they stay legible for users with color-vision deficiency.
HeatLens is a screening tool for identifying priority areas, not a substitute for site-specific, on-the-ground measurement.
We'd love to hear from you — whether you're a city or community organization exploring how HeatLens could support your work, a researcher interested in the data, or just have a question.
Tell us a bit about your project and we'll connect you with providers serving your area.
We'll connect you with providers in your area.