Extreme Heat in Mexico: Deaths Double in a Week, Yucatan Cases Surge

Mexico City — As of May 6, Mexico has recorded seven deaths from extreme heat this season, matching the toll from the same period in 2024 but three fewer than in 2025, according to the federal Health Department (SSA). All 17 fatalities across the three years were caused by heat stroke.

The SSA reported that the week of April 30 to May 6 was the deadliest so far this hot season, with four heat stroke deaths in Chiapas (two), Baja California, and Guerrero. Nationwide, deaths doubled from four to seven between week 16 and week 17, while illnesses rose 36.4% from 217 to 296 cases, including 59 new heat stroke cases, 17 dehydration cases, and three sunburn cases.

In Yucatan, no deaths have been reported, but heat stroke cases nearly doubled from four in week 16 to seven in week 17, moving the state from seventh to fifth place nationally for heat-related illnesses.

Jalisco leads the country with 44 affected individuals (27 dehydration, 14 heat stroke, three sunburn), while Tabasco has the most heat stroke cases at 33 and ranks second overall with 42 patients.

On May 7, the federal Education Department (SEP) announced that, in coordination with all 32 states, the school year will end on June 5 instead of July 15 due to high temperatures and the 2026 FIFA World Cup, which Mexico will co-host with the U.S. and Canada from June 11 to July 19.

According to the SSA, 2023 remains the worst year for extreme heat in Mexico, with 421 deaths and 4,306 cases of heat stroke, dehydration, and sunburn. Globally, 2024 was the hottest year on record due to climate change and the 2023/2024 El Niño, followed by 2023 and 2025. The World Meteorological Organization warned in April 2026 that El Niño could return between May and June.

In Yucatan, 2024 was the deadliest year with 18 deaths and 245 illnesses. So far in 2026, the state has recorded 19 cases (18 heat stroke, one dehydration) from January 1 to May 6, the highest for that period since 2023. In comparison, 2024 had 18 cases, 2025 had 17, and 2023 had six.

Heat stroke occurs when body temperature reaches 40°C (104°F) or higher, according to the Mayo Clinic. Cardiologist Javier Mora Robles and other physicians warn that heat stroke has a mortality rate of up to 70-80% and can cause multi-organ damage.

In Yucatan, air temperatures have ranged from 40 to 43°C from May 1 to 7, but humidity has made it feel much worse. In Merida, the heat index exceeded 51°C on at least three days: May 1, 2, and 6, according to real-time reports from the FIUady weather station.