Panama, Geneva 

Deadly heatwaves which recently hit North and Central America were made 35 times more likely because of human-induced climate change, according to the latest study by World Weather Attribution (WWA). WWA is a collaboration of scientists and analysts including some from the Red Cross Red Crescent Climate Centre.  

Heatwaves began in March across parts of Mexico, Guatemala, Belize, El Salvador, Honduras and the southwest of the United States. Looking specifically at the hottest five days and nights of the most recent extreme heat in early June, the WWA scientists and analysts found that in a world which had not been heated by the 1.2 degrees Celsius of global warming seen to date, the extreme heat would have been very unlikely to have happened. It was made 35 times more likely than it would have been in pre-industrial times, and four times more likely than at the start of this century, just 24 years ago. The researchers say that similar heatwaves would have been expected once every 60 years in the year 2000 but can be expected every 15 years today.

The heatwaves aren’t just getting more frequent. They are getting hotter. For the five hottest days (3-7 June) and nights (5-9 June) they studied, the researchers found daytime temperatures were 1.4 degrees higher than they would have been even in an (extremely rare) ‘heatwave’ in pre-industrial times; night-time temperatures were 1.6 degrees more. As the world warms beyond 1.2 degrees on average, heatwaves in the region will continue to get hotter and even more frequent.

The extreme heat has had many impacts. At least 125 people in Mexico have died because of heatwaves since March. The number across the region as a whole is likely to be much higher as heat-related deaths are rarely recorded appropriately, or not captured at all, because heat-related fatalities are often attributed to preexisting or sudden-onset health conditions rather than the heat that exacerbates or causes them.

One health problem that may be worsened by the heat and other climate-related disasters such as droughts, is mosquito-borne dengue fever. In Guatemala and Honduras, the exponential growth of dengue has forced health officials to declare a red alert. Figures from the Pan American Health Organization show that from 1 January to 25 May this year, cases increased by 622% in Guatemala and 580% in Honduras, in comparison to the same period in 2023. In Guatemala, cases went from 3,738 in 2023 to 23,268 in 2024, while in Honduras they went from 4,452 to 25,859.

In nearby Belize, the heatwaves have led to fires. There have been forest fires in the Toledo and Cayo districts with daily temperatures above 100° F (39°C) creating conditions for fires to start easily and intensify swiftly.  

Across Central America, National Red Cross Societies are dealing with the impacts of extreme heat. In Guatemala and Honduras, volunteers are eliminating mosquito breeding sites, conducting prevention awareness campaigns and providing mosquito nets. Their operations are supported by financial allocations from the IFRC’s Disaster Response Emergency Fund (DREF) and they aim to support more than 20,000 people. A DREF allocation is also helping the Belize Red Cross to support 800 people, providing affected families with hygiene kits, cleaning supplies and cash for recovery efforts. Additionally, members of the national relief corps in Belize are receiving personal protection equipment.  

Karina Izquierdo, Urban Advisor for the Latin American and Caribbean region at the Red Cross Climate Centre, said:  

“Every fraction of a degree of warming exposes more people to dangerous heat. The additional 1.4°C of heat caused by climate change would have been the difference between life and death for many people during May and June. As well as reducing emissions, governments and cities need to take bolder steps to become more resilient to heat.”

Martha Keays, IFRC Regional Director for the Americas, said:

“Extreme heat is a silent threat to the health, economy, and well-being of millions of people in Central and North America. More heatwaves are expected this year and young children, people with disabilities, pregnant women and older adults are particularly vulnerable, as are certain populations who work or spend time outdoors, such as agricultural workers and people on the move. Red Cross teams in the field will continue to assist them, while reinforcing early action and early warning initiatives that help anticipate and protect lives from this and other climate-related disasters.”

For more information, see the full report on World Weather Attribution’s website here 

For more information or to request an interview, please contact: [email protected]

In Panama: Susana Arroyo Barrantes +50769993199  

In Geneva: Andrew Thomas +41763676587