In McAllen, a Texas city along the U.S. border with Mexico, the heat is on … and on and on and on.

From 1979 to 2018, McAllen saw the average number of days per year with a heat index of at least 105 degrees shoot up by 21.9, according to an August 2019 analysis by the nonprofit news organization Climate Central. That was the highest number of days among 239 locations in the U.S. studied by Climate Central. 

This sign in Death Valley, Calif., may come in handy in McAllen, Texas.
This sign in Death Valley, Calif., may come in handy in McAllen, Texas. Credit: Graeme Maclean, CC2.0

As noted by Texas Monthly magazine, the heat in McAllen and nearby cities in Texas’ Rio Grande Valley recently surpassed that of infamously scorching Death Valley, Calif.

On June 8, 2019, for instance, McAllen’s heat index climbed to 119 degrees. Nearly a year earlier, on July 23, 2018, McAllen’s heat index rose to 117. The year before, on June 22, 2017, the temperature (not the heat index) set an all-time record of 111 degrees.

Heat Index Rising

The heat index combines the air temperature and the relative humidity to create a “feels like” temperature. So, when the heat index hits 105, the thermometer itself might be sitting at 100 degrees.

Unfortunately, there appears to be relief in sight for McAllen or any of the other sweltering cities identified by Climate Central.

Its findings are similar to a July 2019 study by the nonprofit Union of Concerned Scientists. It warns that if no action is taken to combat climate change, the number of days per year with a heat index above 105 will quadruple by the middle of the century (2036 to 2065) across the U.S. compared with average conditions from 1971 to 2000.

According to the study, titled “Killer Heat in the United States,” the intensifying heat could cause more deaths or illnesses, and could “disrupt longstanding ways of life, force people to stay indoors to keep cool, and perhaps even drive large numbers of people away from areas that become too unpleasant or impractical to live.”

Sweltering for Those Who Work Outdoors

The scientists’ group notes that one group in particular outdoor workers would face much greater health risks under the scenario outlined in the study. This includes landscapers, construction workers, farm laborers, police officers and postal workers.

Others susceptible to the blistering heat projected in the study include:

  • People in urban areas. Due to what is called the “heat island” effect, temperatures in urban areas tend to be higher than in neighboring suburban and rural communities.
  • People in rural areas, where farmers spend much of the day outdoors and some residents lack air conditioning.
  • Low-income people who don’t have air conditioning or access to air-conditioned places.

Sadly, this is a matter of more than discomfort.

“Heat-related deaths and illnesses are preventable. Despite this fact, more than 600 people in the United States are killed by extreme heat every year,” the U.S. Centers for Disease Control and Prevention says.

10 Cities Where Heat Index Days Are Surging

Here is Climate Central’s list of the cities suffering the biggest increase in the average number of days with a heat index above 105 degrees over the past four decades — along with survival tips for both humans and plants.

1. McAllen, Texas

McAllen, Texas. Credit: Wikimedia
The border city McAllen, Texas, has seen a big increase in extreme heat. Credit: Anthony Acosta

Average increase in the number of days per year with a heat index at 105 degrees or more: 21.9

Survival tip for people: Put in trees and vegetation that directly shade your home.

Survival tip for plants: Add moisture-trapping mulch or compost to your lawn, flowerbed or trees.

2. Laredo, Texas

Average increase in the number of days per year with a heat index at 105 degrees or more: 14

Survival tip for people: Replace an old or broken window-unit air conditioner with a more efficient model.

Survival tip for plants: Choose drought-tolerant plants for your landscape.

3. Victoria, Texas

Average increase in the number of days per year with a heat index at 105 degrees or more: 12.3

Survival tip for people: Subscribe to weather alerts to stay informed about extreme heat.

Survival tip for plants: Water your lawn over a long period to enable the soil to slowly soak up moisture at a depth of 4 to 6 inches.

4. Houston, Texas

Average increase in the number of days per year with a heat index at 105 degrees or more: 9.6

Survival tip for people: Make a list of relatives, friends and neighbors who might need help during extreme heat. Check on them

Survival tip for plants: Mow the lawn frequently and at the proper height to keep the grass healthy.

5. Yuma, Arizona

Average increase in the number of days per year with a heat index at 105 degrees or more: 9

Survival tip for people: Never leave a person (especially a child) or pet alone in a car during hot weather, even if the windows are cracked open.

Survival tip for plants: Put a shade cloth on top of plants to shield them from harsh sunlight.

6. Lake Charles, Louisiana

Average increase in the number of days per year with a heat index at 105 degrees or more: 8.1

Survival tip for people: If you don’t have air conditioning at home, seek out air-conditioned places like libraries, shopping malls and community centers.

Survival tip for plants: Water your lawn deeply just once or twice a week (or as needed) based on rainfall amounts.

7. Tyler, Texas

Average increase in the number of days per year with a heat index at 105 degrees or more: 6.7

Survival tip for people: Avoid eating hot, heavy foods, as they can make you feel even hotter.

Survival tip for plants: Pick a variety of turfgrass that grows well in your area.

8 (tie). Austin, Texas

Average increase in the number of days per year with a heat index at 105 degrees or more: 5.9

Survival tip for people: Drink more water than normal, and don’t wait till you’re thirsty to do it. Avoid caffeinated, alcoholic or sugary beverages.

Survival tip for plants: Water plants in containers and hanging baskets more frequently. They dry out faster than plants in the ground.

8 (tie). Pensacola, Florida

Average increase in the number of days per year with a heat index at 105 degrees or more: 5.9

Survival tip for people: Don’t use your stove or oven, as that generates even more heat indoors.

Survival tip for plants: Watch your lawn carefully to see whether it dries up or fades; if it does, that’s a sign that you’re not watering it enough.

10. Lafayette, Louisiana

Average increase in the number of days per year with a heat index at 105 degrees or more: 4.7

Survival tip for people: Limit outdoor activities to the morning and even hours, when the temperature is lower.

Survival tip for plants: Water your lawn a couple of hours before sunrise, when winds tend to be lighter and temperatures tend to be lower, to avoid evaporation.

Main image credit: Luca Castellazzi

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