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Know the West

The West’s hottest county is also its most Latino

Some places in Imperial County, California, experienced 117 days above 100 degrees this year.


People walk downtown as the temperature reached around 115 degrees in June in Calexico, California.
Sandy Huffaker/Getty Images

For much of the West, the record-breaking summer heat has finally given way to comfortable fall temperatures. But in Imperial County, California, the early October days still surpassed 100 degrees Fahrenheit.

Though every county in the Western U.S. is experiencing rising temperatures, Hazardous Heat, a report published in August by the First Street Foundation, revealed that Imperial County is by far the region’s most extreme case. El Centro, the county seat, had already experienced 117 days over 100 degrees this year by Oct. 3. (Only one other Western county — Yuma, Arizona — cracked the report’s list of the 20 hottest counties, meaning those with the most days above 100 degrees; in California, only one other county, Riverside, currently experiences even 30 days above 100 degrees.)

This isn’t just a grim statistic; it’s a climate justice issue. Not only is Imperial the West’s hottest county, it’s also the region’s most Latino; over 85% of its residents identify as Hispanic or Latino. This is no coincidence: Imperial, which boosters call “America’s Winter Garden,” is a border county, and the agricultural industry depends on immigrant farmworkers.

Additionally, Imperial is poor: More than a fifth of the residents live in poverty, and a third lack air conditioning.

A lot of people don’t have money for utilities, said Maribel Padilla of the Brown Bag Coalition, a group of volunteers who feed the county’s unhoused community every night. People with cars can take advantage of the air conditioning at the community center or library, she said, but the county’s sprawling agricultural geography makes it hard for those who lack transportation — it’s much too far to walk, especially in the heat. Every year, both housed and unhoused residents of Imperial County die from the heat.

The environmental impacts hit our communities before the solutions arrived, said Luis Olmedo, executive director of the farmworker-founded organization Comité Civico del Valle.

Understanding how the Dangerously Hot Days, defined as having a “feels like” temperature of 100℉ or more, are projected to increase into the future can help communities better prepare for energy usage and protect constituents who might be more susceptible to hospitalization or death at higher temperatures. Imperial County is expected to see 102 Dangerous Days this year, growing to 116 a year by 2053, an increase of 14 days.
First Street Foundation

The extreme heat is exacerbating existing environmental justice concerns in several ways:

High temperatures make agricultural labor more dangerous — and more precarious. Outdoor workers are 35 times more likely to die from excessive heat than indoor workers. The heat not only causes heat stress and heat stroke, it also exacerbates pre-existing respiratory and cardiovascular conditions.

On top of this, the heat forces low-income workers to make a choice between their health and their livelihood. Outdoor workers in the Imperial Valley currently lose more than three workweeks a year to heat, and that figure is projected rise to 48 days by the end of the century.

Heat is worsening the county’s already-high rates of asthma. The Imperial Valley has some of the nation’s highest rates of pediatric asthma, with one study showing that over 22% of elementary school children suffered from the condition. There are a number of reasons for this: Agricultural activity stirs up dust, and in the fall, farmers burn fields to get rid of Bermuda grass and other stubble. Additionally, truck traffic and emissions from assembly plants in nearby Mexicali create smog. The valley’s topography prevents these particulates from blowing away, while the heat intensifies the chemical reactions that produce smog and ground-level ozone.

The impact of these Dangerous Days are heightened when they are experienced in succession, known as Consecutive Dangerous Days. This year, in Imperial, the expected length of Consecutive Dangerous Days is 53 days. In 30 years, Imperial County can expect to have as many as 74 Consecutive Dangerous Days, an increase of 39.6%. (Imperial County is in dark red.)
First Street Foundation

The warming and drying climate is also desiccating the nearby Salton Sea, which was used for decades as a dump for pesticide-saturated agricultural runoff. Now its dry lakebed is filled with toxic dust that adds particulates to the air.

Hot temperatures can increase pesticide toxicity. California’s hottest areas also have some of the state’s highest rates of pesticide use. According to CalEnviroScreen, pesticide use is higher in the Imperial Valley than in about 90% of the rest of the state. Near Holtville, east of El Centro, the Imperial County seat, around 2,200 pounds of pesticides are applied per square mile every year.

And hotter temperatures are increasing workers’ exposure to these toxic chemicals. This is partly because climate change is bringing more pests that require higher amounts and more frequent applications of pesticides. At the same time, the rising temperatures increase human sensitivity to the chemicals. Heat stress causes changes in blood flow, sweating and respiration, and this can increase chemical exposure, one study suggests. The heat also makes it less likely that workers will wear protective layers of clothing.

All this affects residents’ mental health. Just having the concern and uncertainty can trigger asthma, high blood pressure and other cardiovascular impacts, said Olmedo. It reduces quality of life.

The COVID-19 pandemic made these mental health outcomes worse. One new study found that during the pandemic, 40% of Latina farmworkers in Imperial County had stress levels high enough to be considered clinical mental health risks. COVID kicked us when we were down, said Olmedo.

In an aerial view from a drone, the remains of a former yacht club are seen in 2021 in Salton City, California. As the lake continues to evaporate, its increasing salinity has made it unsustainable for the fish and great masses of white pelicans and other migratory birds that fed on them. As more lake bottom becomes exposed, fine particles of toxic dust are becoming a health hazard to local communities.
David McNew/Getty Images

What should be done? Imperial County’s situation clearly shows that low-income communities of color are bearing the brunt of climate change and its impacts. Comité Civico del Valle and other organizations are attempting to address the environmental injustice by creating the state’s largest air-monitoring network and improving access to culturally informed health care.

Meanwhile, wealthy communities are using resources and political power to direct climate mitigation resources toward their own homes. But any serious efforts to mitigate the effects of climate change have to start with those who are most at risk, Olmedo said.

In disasters, you triage. But we’re not triaging the climate; it’s still a negotiation between the affluent and the poor about who should get resources to adapt. Success is helping the most vulnerable.

Caroline Tracey is the Climate Justice Fellow at High Country News. Email her at [email protected] or submit a letter to the editor. See our letters to the editor policy.