Puerto Vallarta, Mexico – Fires around the Bay drive Puerto Vallarta air quality into ‘unsatisfactory’ territory, exceeding 130 IMECAs and prompting health warnings amid smoke lingering for weeks.
Smoke from weekend forest fires in the hills surrounding the Bay has pushed Puerto Vallarta’s air quality into the “unsatisfactory” zone. Meteorologist Víctor Manuel Cornejo López, advisor to the Scientific Council of Civil Protection of the Bay, reported readings above 130 on the Metropolitan Air Quality Index (IMECA). At those levels, irritations in the eyes, nose and throat can afflict sensitive groups and even healthy adults.
Cornejo López explained that much of the smoke sits in the higher layers of the atmosphere, where it alters the sky’s hue. “People notice a reddish or yellowish tint, and the sunlight feels dimmer,” he said. At ground level, the smoke registers through odor more than sight. But the IMECA readings—often rising to 120 or 130 in some neighborhoods—reflect the volume of fine particles in the air regardless of visibility.
By definition, IMECA scores between 101 and 200 fall into the “unsatisfactory” category. That range signals air quality that can provoke discomfort for the elderly, children and those with heart or lung conditions. At scores above 150, even healthy adults may feel throat irritation, pounding headaches or dizziness after prolonged exposure. Cornejo López urged residents to cut back on outdoor exercise, avoid parks and playgrounds, and keep windows closed when possible.
“Breathing this air for hours can harm anyone,” Cornejo López warned. He noted that while elderly residents and young children face the highest risk, symptoms like coughing and shortness of breath can show up in all age groups. Local clinics have reported a modest uptick in patients with respiratory complaints since the fires began. Medical experts worry that continued exposure could aggravate chronic conditions such as asthma or bronchitis.
Health authorities considered declaring an air quality pre-contingency, a step that would temporarily halt school recess and outdoor work. The regional Civil Protection agency has not yet issued an official alert, but they stand ready to act should IMECA readings climb further. “We could see brief spikes past 150 if the wind shifts,” Cornejo López said. “That would trigger immediate restrictions on outdoor activities.”
Looking ahead, he predicted smoky skies for at least the next several weeks. Mountain ridges and valleys trap the haze in pockets, sending it drifting over populated areas when the wind eases. “Expect IMECA levels between 50 and 70 for a few days, but the smoke will return to above 100 as long as the fires burn,” he added. Firefighters continue to battle blazes in remote areas, but rugged terrain and dry vegetation slow progress.
Public officials remind residents that IMECA serves as a daily guide to air pollution’s health impacts. The scale runs from 0 (clean) to 500 (hazardous). Values above 200 enter the “harmful” category, prompting health alerts for everyone. At present, readings at or above 130 sit squarely in the “unsatisfactory” range—high enough to warrant caution but just below the threshold for official contingency measures.
The Fact: The Metropolitan Air Quality Index (IMECA) ranges from 0 to 500. Higher values signal worse air pollution and greater health risk.
Puerto Vallarta, Mexico - Fires around the Bay drive Puerto Vallarta air quality into ‘unsatisfactory’ territory, exceeding 130 IMECAs and prompting health warnings amid smoke lingering for weeks.
