There is a line in this year's global climate reporting that is easy to read past and worth stopping on: the past eleven years are the eleven hottest on record. Not "among the hottest." The hottest, in order, clustered at the end of the series. The United Nations Environment Programme summarized the broader picture bluntly this season — that the damage now extends well beyond temperature itself, into polluted air, degraded land, collapsing ecosystems, and vanishing biodiversity.
As the 2026 heat season opens in our region, we want to translate that record out of the global dashboard and onto the block, because that is where it actually lands.
Heat is not distributed evenly, and that is the whole story
The single most important thing our data shows, year after year, is that a "hot day" is not one temperature across a city. On the same afternoon, two neighborhoods a few miles apart can differ by ten degrees or more. The difference is built, not natural: tree canopy, pavement, building density, and the presence or absence of green space. Asphalt and rooftops absorb and re-radiate heat; trees and soil shed it. Neighborhoods with less canopy and more hard surface — which, in city after city, tend to be lower-income neighborhoods and communities of color — run hotter and stay hotter into the night.
That last part matters most for health. The danger of extreme heat is not only the peak at 3 p.m.; it is the night that never cools down, denying the body the recovery it needs. Our temperature loggers consistently show the starkest neighborhood gaps after sunset, which is exactly when the risk compounds.
What the data is for
Mapping heat is not the goal. Acting on it is. The reason we run a network of sensors and pull satellite-derived surface-temperature data is to answer practical questions for the people making decisions:
- Where do cooling resources go first? Heat maps let a city target cooling centers, water distribution, and wellness checks to the blocks that need them most, rather than spreading them evenly across blocks that are not equally at risk.
- Where does tree canopy buy the most relief? Planting is a multi-decade investment, and our data helps direct it to the hottest, least-shaded areas where each tree does the most good.
- Who needs a knock on the door? Overlaying heat data with information about older residents and people living alone helps responders prioritize during a heat emergency.
What you can do as the season starts
- Know your own block's risk. If your street is short on shade and heavy on pavement, treat heat advisories as more serious than the regional forecast suggests. The regional number is an average; your block may run well above it.
- Check on neighbors at night. The overnight low is the hidden danger. A quick check on an older or isolated neighbor during a heat wave is one of the highest-value things an ordinary person can do.
- Push for canopy and cool surfaces. Tree-planting programs, cool-roof initiatives, and shade at transit stops are not amenities. In a record-heat era they are public-health infrastructure, and they are worth advocating for at the local level.
The eleven-hottest-years statistic is the kind of number that can make a person feel small. The antidote is to make it specific. We cannot change the global record from here, but we can know which blocks will suffer most this summer, get help to them first, and plant the canopy that makes next decade's heat season survivable. That is what the data is for.
