The calendar may have barely turned to spring, but residents of 12 states might consider  skipping ahead to their summer clothes going into the weekend.

The National Meteorological Service (SMN) forecast extreme heat in several northern and western states for Friday and into the weekend, advising residents to stay well-hydrated, to avoid prolonged exposure to the sun and to wear long-sleeved, light-colored clothing during the day.

With temperatures expected to soar above 105 F (40 to 45 C) in Baja California, Sonora, Chihuahua, Sinaloa and Guerrero, the SMN is urging residents to pay special attention to children, the elderly, the chronically ill and vulnerable groups.

Temperatures of 95 F to 104 F (35 to 40 C) are expected in Baja California Sur, Durango, Zacatecas, Nayarit, Jalisco, Colima, Michoacán, Morelos, Puebla, Oaxaca and Chiapas, while Coahuila, Nuevo León, Tamaulipas, San Luis Potosí, México state, Campeche, Yucatán and Quintana Roo will see highs of between 86 and 95 F (30 to 35 C).

The heat wave in the north is expected to begin weakening by Monday, but that does not imply a significant drop in temperatures. On the contrary, the SMN warned that a possible increase in humidity could lead to muggy mornings that lead to warm afternoons.

Climatological recordings show that meteorological springs in Mexico have become increasingly warmer and drier over the last decade, according to Meteored México. 

“The beginning of March now presents temperatures that were previously typical of mid-April, bringing forward water stress in sensitive ecosystems,” it said.

The National Water Commission (Conagua) reported that a progressive increase in solar radiation and a decrease in the influence of cold fronts will produce an increase in temperatures during the second half of March and through April.

May is typically the hottest month across Mexico and Conagua has predicted persistent heat waves throughout the year, projecting that several Mexican cities could see record-breaking temperatures in 2026.

Hermosillo, the Sonora state capital, and Mexicali, capital of Baja California, have already done that.

On Wednesday, Mexicali set a new record for March when the temperature topped out at 105.6 F (40.9 C). In Hermosillo, the mercury hit 108 F (42.5 C), a new record for March, on Thursday.

The SMN recorded five heat waves in 2025, with the highest temperatures concentrated in mid-May.

With reports from N+, La Jornada, La Prensa, El Sol de Sinaloa and Yale Climate Collections