New urban heat island study shows surprising variation in air temperatures across Twin Cities

http://www.eurekalert.org/pub_releases/2015-11/uom-nuh111815.php

Public Release: 18-Nov-2015
New urban heat island study shows surprising variation in air temperatures across Twin Cities
Results provide valuable insights into efforts to reduce heat-related harm in metro areas globally
University of Minnesota

Some parts of the Twin Cities can spike temperatures up to 9°F higher than surrounding communities thanks to the "urban heat island" effect, according to a new study from the University of Minnesota.

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Recording surface air temperatures every 15 minutes from August 2011 through August 2014 across nearly 2,000 square miles and using U.S. Geological Survey data to fine-tune differences at the neighborhood level, the study uncovered several surprises. Among them:

Temperatures in the urban core of Minneapolis, St. Paul and Bloomington average 2 °F higher in summer than in surrounding areas

The differential spiked as much as 9 °F higher during a heat wave in July 2012

Urban heat island effect is stronger at night in summer and during the day in winter

In urban areas during the winter when snow cover is less pervasive, temperatures are higher than rural areas in the daytime by an average of 2 °F.

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The more detailed understanding of urban heat islands provided by the study can help health professionals and others target efforts to protect people and infrastructure from heat-related problems, according to project co-leads Tracy Twine and Peter Snyder, associate professors in the College of Food, Agricultural and Natural Resource Sciences.

"This level of detail in real time can provide specific information to agencies tasked with protecting our citizenry during extreme heat events," Snyder said. "It can also be used to identify persistently warm areas of the metro where green infrastructure projects could be implemented to offset some of the warming."