More than 70 volunteers spent their hot and muggy Saturday driving around the metro area to measure the heat via sensors attached to their vehicles.

The sensors captured temperature, humidity, air quality, time and location.

It’s part of a national study. Hennepin and Ramsey counties were chosen to participate in the National Oceanic and Atmospheric Administration’s 2024 Urban Heat Island Mapping Campaign to map out the hottest neighborhoods in 14 communities nationwide and four cities abroad.

The study is focused on what researchers refer to as “urban heat islands,” which are areas concentrated with buildings.

“Areas that have a higher density of buildings and pavement have a harder time cooling down, which means that residents in highly dense urban areas are at greater risk of suffering the consequences of extreme heat,” said Abi Phillips, the Ramsey County, Climate & Health Program Supervisor.

The new data will be paired with community engagement, analysis, and modeling.

Ramsey County said the data will also help officials strategize the next steps to reduce the health impacts in the hardest hit areas as part of its Climate Equity Action Plan.