New study gets urban heat islands on map

Rennie Gaither

Happy Summer! I was born on July 4th, much to the chagrin of my younger sister. “Everybody celebrates Rennie’s birthday,” she said, dejectedly, beneath thick, swollen braids, “No one likes mine.” She had, however, the satisfaction of our being the same age for four days every summer when the sun burned wickedly and marauding mosquitoes tore through our skin.
I recalled those summers last July when I participated in a study to better understand urban heat and air quality throughout the Twin Cities. Ramsey and Hennepin counties funded this citizen science project dubbed The Urban Heat Island Study with support from the National Oceanic and Atmospheric Association.
Ramsey County trained me and other volunteers to mount heat and air quality sensor devices on our vehicles and drive planned routes throughout the county three times daily – morning, afternoon, and evening. Each drive took around an hour. A two-person team gathered data. We turned on the air conditioner, kept to the speed limit, and followed our route with acute attention to detail. The relaxing, leisurely drive around St. Paul bubbled with conversation and new sights, heretofore hidden in plain sight.
In total, the Twin Cities project covered approximately 400 square miles, enlisted 128 volunteers driving 34 routes, and involved 227,127 measurements.
Results arrived six months later and yielded unsurprising data to many of us in the environmental community: higher temps on average for developed urban areas (downtowns, for example); industrial areas transferred higher temps to nearby residential areas; and trees, green space, and lakes and waterways offered high temperature alleviation.
The study also produced maps that showed heat pockets (heat islands). Such detailed geographic data can help government agencies and community nonprofits such as Frogtown Green and others develop projects to better address heat island affects, whether that be focused tree planting, more diverse land-use and land-cover design planning, and/or support of further research into heat and air quality dynamics. Read the Urban Heat Island report at https://www.ramseycounty.us/climate-action/urban-heat-island-study. 
So, how to stay cool? The Ramsey County Public Health department and other public health providers suggest a number of heat reduction options including installing green or reflective roofs, using energy-efficient appliances, or simply making use of blackout curtains or shades to block the hot afternoon sun. Heat waves should also be a time for regularly checking on heat vulnerable friends and family. Staying hydrated, cooling off, and staying informed about weather are essential to combatting potential heat-related health hazards.
And don’t forget the trees! In Frogtown, residents can once again order a free fruit or shade tree to help bring “nature’s air conditioner” to their front or back yards. Similar programs exist in Hamline-Midway, Summit-University and on the near East Side. Check out Frogtown Green’s program at frogtowngreen.com
P.S. If you want more tips on dealing sustainably with everything that climate change is throwing at us (from heat waves to downpours to increased smoke in the air) don’t miss Frogtown Green’s 2025 Climate Carnival, coming up on Saturday, Aug. 16, from 1-4 p.m. Stop by the Carnival site (at 625 Dale Street, the southwest corner of Lafond and Dale) for carnival games with prizes, special resources and energy-efficient giveaways, and a delicious lunch from Frogtown Green and friends. Details at frogtowngreen.com/events
Rennie Gaither is a Frogtown Green volunteer. Frogtown Green is a resident-led and volunteer-powered environmental initiative in St Paul’s most diverse neighborhood. If you’d like to know more, browse frogtowngreen.com or call 651-757-5970.