Our heat map shows a 9-degree gap between the city’s hottest and coolest blocks

Neighborhoods with the fewest trees ran the hottest on summer afternoons.

A hazy, smog-covered horizon

On the hottest afternoons of the summer, some Port Avalon blocks were nearly 9 degrees Fahrenheit hotter than others, according to a Draft analysis of temperature readings from 140 sensors placed by volunteers.

The hottest blocks, mostly in Lowmarsh and the industrial east side, had the least tree cover. “Shade is infrastructure,” said urban forester Leah Okafor, who reviewed the analysis.