US air quality map: A Code Purple alert for poor air quality has been declared in Philadelphia due to smoke from wildfires in Canada. A first alert has been issued for the Philadelphia area because of deteriorating air quality, following the arrival of smoke from Canadian wildfires and northern Minnesotan wildfires on Thursday, which is anticipated to persist until Saturday.US air quality map: Philadelphia has issued a Code Purple air quality alert as smoke from Canadian and Minnesotan wildfires impacts the region. (Getty Images via AFP)The Pennsylvania Department of Environmental Protection (DEP) has issued a Code Purple air quality alert for the entire state today. Earlier, Allegheny County was under a Code Maroon alert. A Code Maroon (the most severe) or Code Orange (less severe) alert may be issued today, depending on the specific location.All residents are advised to refrain from engaging in prolonged or strenuous outdoor activities during Code Purple alerts, as per the DEP.Vulnerable groups, including children, the elderly, and individuals with respiratory conditions, should completely avoid outdoor activities.Additionally, people are encouraged to refrain from using gas-powered lawn equipment and from lighting campfires.Smoke in Butler CountyThe smoke arrived in Butler County late yesterday morning, progressing southward into the city by early afternoon, and completely covering the area by evening.According to the National Weather Service, it is expected to linger over the region throughout today, with a possibility of beginning to clear from Southwest Pennsylvania by late tonight.The smoke emanating from over 100 wildfires currently raging across Ontario follows three years after wildfire smoke from Canada transformed the skies in the region into an unsettling orange and gray hue, obscuring landmarks and rendering the Philadelphia skyline nearly invisible.Also Read: Vanessa Trump health: Kai Trump gives update on mother after cancer surgeryExperts warn residents about health issuesAs the smoke approaches the Philadelphia area, medical professionals are cautioning residents about the possible health implications.Dr. Leah Lande, a pulmonologist affiliated with Lankenau Medical Center, stated that wildfire smoke comprises harmful gases, ozone, and fine particulate matter that can present significant health hazards, particularly for children, the elderly, and individuals with heart or lung ailments.Health authorities are advising residents to minimize unnecessary outdoor activities, keep windows shut, and remain in air-conditioned environments whenever feasible over the coming days.To maintain clean indoor air, the Philadelphia Health Department recommends the following actions: close all windows and doors, turn off air conditioning or set air conditioners to recirculate mode, refrain from activities that generate additional particulate matter indoors, such as smoking and vaping, utilizing gas, propane, or wood-burning stoves and heaters, spraying aerosol products., frying or broiling food, burning candles or incense and vacuuming, unless using a vacuum equipped with a HEPA filter.If you don't have an air conditioner, remaining indoors with closed windows may pose risks during hot weather. If you feel overheated, it is advisable to seek a location with air conditioning, as noted by the health department.When to seek medical attentionDr. Lande advised that individuals should pursue medical attention if they encounter: chest tightness, shortness of breath, coughing , wheezing and rapid or irregular heartbeatShweta Kukreti has over 8 years of experience in covering Indian and world politics. She joined the Hindustan Times in 2024 and is primarily assigned to the US desk. She currently works as Deputy Chief Content Producer and reports on a wide range of topics, including US politics, immigration issues (especially H-1B visa) and major global events. Shweta strongly emphasizes team operations, which encompasses monitoring news, delegating tasks, editing, developing comprehensive coverage strategies, and crafting engaging, and data-informed narratives. She received the Digi Star Award at the Hindustan Times within a year of joining for her broad coverage of US politics. In 2025, she earned both a promotion and a redesignation, a significant achievement recognising her contributions and the strong value she brings to the team. She has previously worked with the Indian Express, HTDS, ANI and Republic World. Seniors in all the media organisations recognised her work. Regarding education, she earned a BA (Hons.) in Political Science and a master's degree from Delhi University, and she pursued a PG Diploma in English Journalism from the Indian Institution of Mass Communication (IIMC). She also holds a diploma in Women's Empowerment and Development from IGNOU University and a French certification course from Alliance Française de Delhi. If not working, you can find her exploring the hills and engaging in adventurous activities in Rishikesh and Himachal Pradesh. She loves to play badminton, volleyball, and chess, and spend time with her friends and family. She also enjoys spiritual activities.Read MoreSee Less