The hot season is approaching Mexico, and with it, environmental contingencies, drought, and heat waves are expected in certain areas of the country. Last year, the drought caused water levels in the Cutzamala System reservoirs to reach one of their historical lows at 39.8% capacity. Additionally, Mexico City recorded a record number of environmental contingencies due to atmospheric stability that concentrated pollutants in the air. As for high temperatures, a historical record of 34.7 degrees was reached on May 25 of last year.
For 2025, the Meteorological Service of Conagua predicts up to five heat waves between February and June in Mexico. These are expected to be similar to previous years, with no significant increase in maximum temperatures. However, there could be a longer duration of heat waves, as observed in recent years with warm periods extending over weeks.
Conagua points out that heat waves in Mexico show an upward trend regarding duration and persistence. Since 2010, the annual average of heat waves has increased, remaining at more than four per year since 2020. In 2009, 2019, and last year, up to six heat waves were recorded respectively, becoming more frequent heat periods compared to previous decades. Moreover, the duration of heat waves has extended from four to six or seven days on average since 2020.
The regions most affected by heat waves in Mexico are Mexico City, the State of Mexico, and Hidalgo, where increases in the duration of warm periods are reported year after year. In Hidalgo, heat waves last approximately 0.6 days longer each year, while in the State of Mexico, Puebla, and Querétaro, they increase by 0.3 days, and in Mexico City, Tlaxcala, and Morelos, by 0.2 days.
