Stories tagged heat


The Science Museum of Minnesota is a partner with the University of Minnesota on its Islands in the Sun project, which is monitoring the urban heat island in the Twin Cities to find ways of lessening its effects through landscape design. More than half the global population now lives in cities and so there is urgent need to understand and mitigate urban heat islands, especially during heat waves when the risk of heat-related illness and mortality can increase dramatically.Islands in the Sun temperature sensor
Islands in the Sun temperature sensorCourtesy Courtesy Department of Soil, Water and Climate, University of Minnesota

Islands in the Sun is setting up temperature sensors throughout the Twin Cities Metro Area. This temperature network when completed will be one of the densest in the world. Would you like to be a part of this effort? Islands in the Sun is especially interested in volunteers willing to have a sensor installed on their property and who live in the following locations -- downtown Minneapolis, downtown Saint Paul, Saint Paul – east of Rice St, West Saint Paul, South Saint Paul, Mendota Heights, Inver Grove Heights, Eagan, Oakdale, Woodbury, Cottage Grove, northern Roseville, Arden Hills, and Plymouth.

Information about the sensor and its placement can be found here. If you are still interested after reviewing this information, then fill out and submit a volunteer form. Please note that your interest does not guarantee that a sensor will be installed because each site must meet certain criteria. If selected, a temperature sensor will be installed at a location on your property acceptable to you with the expectation that it will remain onsite collecting data for up to four years. A technician will visit the sensor every two to three months to download data.

Thanks for considering being a part of this ground-breaking research project.

Not that you probably couldn't guess this, but it's now official. July of 2012 was the hottest month ever in the United States, topping the aggregate temperature record for a month set during the middle of the Dust Bowl years in 1936. You can read all the steamy data on this record here.


Radiometers at Science Museum of Minnesota
Radiometers at Science Museum of MinnesotaCourtesy Patrick Hamilton
The Minneapolis-St. Paul International Airport reported a low at 6:00 a.m. this morning of 73 degrees F degrees while nearby Lakeville was at 57 – a 16 degree difference in only 20 miles. Said Paul Huttner, an MPR meteorologist, “…one of the biggest urban heat island effects today I have ever seen in 40+ years of watching and forecasting weather in the Twin Cities.”

Urban heat islands are regions of strong warming localized around the heart of a city with progressively lower temperatures as one travels away from the center – hence the name “heat island”. Urban heat islands exist because of large differences in land use, building materials, and vegetation between cities and their rural surroundings. In much of the world, cities are warming at twice the rate of outlying rural areas and so the frequency of urban heat waves is projected to increase with climate change through the 21st century.

Drs. Peter Snyder and Tracy Twine are in the midst of a four-year research project funded by the University of Minnesota’s Institute on the Environment and the College of Food, Agriculture, and Natural Resource Sciences to monitor the urban heat island of the Twin Cities. The project aims to improve understanding of the mechanisms contributing to urban heat islands with a goal of finding ways to lessen their effects through landscape design.

Snyder, Twine and two graduate students installed two instrument towers at the Science Museum on Monday as part of their urban heat island research project. One is on the white roof outside of the windows of Elements Café and the other is on a nearby black roof. Both are visible if you stand at the southwest corner of the plaza outside of the Café and look back at the museum. The two towers with their arrays of temperature sensors and radiometers will collect data at the museum for about four weeks, permitting Snyder and Twine to better characterize the interactions between different roof types and solar radiation in their urban heat island modeling work.

Flowerpots in full flame
Flowerpots in full flameCourtesy GatheringZero
In my continuing quest to keep the public informed about exploding household objects, I bring you the case of the exploding......FLOWERPOT house fire?! I’m sorry but of all the things that could explode, a flowerpot falls pretty low on my list of potential hazards. The St. Paul Fire Department investigator, James Novak, agrees, “It’s not like everybody has to worry that their house is going to burn down...halogen lights, smoking, candles and Pop-Tarts in a toaster--there are a lot of things higher on the priority list than a potted plant fire.” Nevertheless, the combination of fertilizer, heat and oxygen within the pot can lead to potentially unorthodox flower pot behavior. Consider yourselves warned. As for me, I think a conversation with my fern about fire safety is long overdue.


White roofs reflect heat, leaving the structures below cooler: Photo by gadfly pro from
White roofs reflect heat, leaving the structures below cooler: Photo by gadfly pro from

Looking for an easy way to reduce global warming, and save yourself a few bucks in the process? Paint your roof white! Most rooftops in America are black or some other dark color. These absorb heat, making the building hotter and less comfortable. People in the building run fans and air conditioners to cool off. Not only do they spend more on energy, but the power companies have to burn coal and oil to produce the electricity.

But a white roof reflects heat. The building stays cooler, and needs less electricity.

For maximum effect, you should use special heat-reflective materials. And keep the roof clean – dust and dirt darken the roof, reducing its reflective properties.

It’s been estimated that if every roof in the world were white, it would counteract all the global warming of the last 30 years! Now, the authors of this study admit that they used a very simple model – climate is much more complicated than their equations allow – but still, like changing your lightbulbs, this seems like an easy way to start having an impact now. In California, the government is giving rebates to building owners who install cool roofs.


It's cold this morning. Maybe the coldest morning of the season so far? Luckily, there's also a lot of sunshine, and almost no wind.

If it were windy, you'd hear the weather forecasters talking a lot not only about the air temperature (-6 degrees when I left the house), but also about the "wind chill." Wind chill is a way to describe how quickly heat is transferred from your body to the atmosphere when it's both cold and windy outside. As wind increases, more heat is drawn from your body, decreasing your skin temperature and eventually your internal body temperature. Wind chill makes it feel much colder than it actually is.

Last year, I overheard a woman in the Science Museum parking garage elevator talking about how she parks her car in a sheltered area to protect it from wind chill. She was worried that, if she left it in a more exposed area, it wouldn't start. I can't say anything about the state of her car battery, or condensation on her distributor, but I can say that wind chill has very little impact on cars or any other inanimate objects: wind will shorten the time it takes for an object to cool to the temperature of the surrounding air, but it won't get any colder than that no matter how much wind there is.

For humans and animals, though, wind chill affects how quickly hypothermia and frostbite can occur. Hypothermia is a condition in which core body temperature has fallen to the point where normal muscle and brain functions are interrupted. (Thor did a post about hypothermia a few weeks ago.) Frostnip/frostbite are conditions in which body tissues freeze. Knowing the wind chill helps us make decisions to avoid these and other cold weather dangers.

She's got the right idea: Bundle up! (Photo by Yann Richie)
She's got the right idea: Bundle up! (Photo by Yann Richie)

The best thing to do when there's a significant wind chill is to stay inside. But you can't stay at home on the sofa all winter. So what can you do? Dress right when you go outside. That means wearing several layers of loose-fitting, lightweight, warm clothing. (Trapped air between the layers will insulate you and keep you warm.) Stay dry. (Remove layers if need be to avoid sweating and later being wet and cold.) Wear a tightly woven, water repellent, hooded top layer. Cover your mouth to protect your lungs from the cold. Mittens, which allow your fingers to share warmth, are better than gloves. And your mom was right: wear a hat! Half your body heat can be lost from your head.