Spokane heat deaths ‘completely avoidable’: Gonzaga group maps ‘urban heat islands’ to better understand city hot spots

Last summer’s continuous scorching temperatures killed 20 people in Spokane County, more than the previous eight years combined, according to county officials.

“It just really struck us,” said Brian Henning, director of Gonzaga University’s Center for Climate, Society, and the Environment.

Henning, members of the Center for Climate and community volunteers drove on Saturday through Spokane neighborhoods mapping out “urban heat islands” with the goal of sparking action to better prepare Spokane for the next heat wave. Urban heat islands are areas, including pavement and buildings, that absorb and retain heat and can be much hotter than other shaded parts of neighborhoods.

“It’s important that we begin to think concretely. How do we protect those most vulnerable members of our community?” Henning said. “No one in Spokane in the 21st century should be dying of extreme heat. It’s completely avoidable.”

The Center for Climate launched “Spokane Beat the Heat” in response to the 2021 heat dome deaths. Henning described a heat dome as an extended period of high pressure that lingers over an area, resulting in high daytime and nighttime temperatures. The goal of Beat the Heat is to help the community understand and respond to future heat waves so that no one dies of extreme heat, Henning said.

The National Oceanic and Atmospheric Administration funded Saturday’s urban heat island mapping campaign with a $10,000 grant, Henning said. Spokane was one of 14 U.S. cities and counties the NOAA chose for the campaign, and the only one in the Northwest. Other cities included Jacksonville, Florida; Milwaukee; Boulder, Colorado; Clark County, Nevada, which includes Las Vegas; Philadelphia; Brooklyn, New York; and San Francisco.

The Center for Climate partnered with the Spokane City Council Sustainability Action Subcommittee, the Lands Council, 350 Spokane and KXLY-TV for the grant.

“This grant, and this campaign, provided an opportunity to get real concrete data that demonstrates the urban heat island effect in our community specifically,” said Karli Honebein, program coordinator of the Center for Climate.

Henning and other drivers Saturday attached a sensor to a passenger window of the car that measured the temperature and humidity outside every second they were driving. The volunteers, including high school students and retirees, completed routes at 6 a.m., 3 p.m. and 7 p.m. Henning said the routes covered the entire city.

Community members submitted points of interest they wanted included in the routes, Henning said. Parks, parking lots, shopping and community centers and libraries were some landmarks people were interested in investigating.

He said NOAA officials drew routes that intersected with as many of those landmarks as possible and included a diverse sample of well-shaded areas and urban heat islands.

The tens of thousands of data points collected will then be used to create high-resolution heat maps of Spokane, Henning said. The maps will take six to eight weeks to complete.

Henning said the maps will show heat disparities in neighborhoods. For example, some areas of the South Hill have more than 40% tree canopy coverage, while places in northeast Spokane have less than 15% coverage, he said. The well-treed South Hill area is likely to be cooler.

While data was not available Saturday, Ben Brown, a Gonzaga senior majoring in environmental studies and economics, provided an example of heat disparities on his college campus. Brown used an infrared camera on a 90-plus degree day last week at Gonzaga. One pavement area in the sunlight showed a surface temperature of around 125 degrees, while a nearby shaded pathway was about 50 degrees cooler.

Extreme heat is a deadlier weather hazard than all other weather events combined each year, according to Honebein.

For Spokane, extreme heat refers to days with high temperatures of at least 90 degrees and low temperatures of at least 68, Henning wrote in an email. People, especially vulnerable seniors and young children, in hot conditions are at risk for heat-related illnesses.

Last summer’s heat deaths were spread across Spokane, with most of them happening north of Interstate 90. Henning said part of the problem during last year’s heat dome was the temperature did not get cool enough at night, wreaking havoc for vulnerable people and those without air conditioning or with poorly insulated homes.

Henning said the next step for the Center for Climate is distributing a 50-question survey to Spokane residents to learn about their perceptions and experiences with extreme heat. Part of the survey will try to gauge a sense of how many people have air conditioning, and whether can they afford to use it if they do.

Henning said he will then provide the mapping and survey data to city officials, Avista Utilities, Spokane Neighborhood Action Partners and other agencies who are trying to prepare for extreme heat conditions. He said the Center for Climate will advocate for building community shelters that provide air conditioning, backup generation and air filtration to combat smoky conditions, so people have a place to go in hot weather.

Planting trees is another action agencies can take in less-shaded areas.

“They’re gonna have real information about neighborhoods and how warm they are during extreme heat events,” Honebein said. “And so it’s really providing data that’s going to allow the city to chart a path forward so that less people die.”