Baltimore air quality alert issued as heat and ozone build up

Parents at youth practices, construction crews, delivery workers and older Baltimoreans should plan around the noon-to-5 p.m. window Monday and Tuesday, when heat and light winds are expected to let pollution build across the city. The Maryland Department of the Environment says young children, older adults and people with asthma, heart disease or lung disease should cut back outdoor time as ozone rises.

Maryland’s 3-day air quality forecast covers 10 regions, and the ozone outlook runs from April through September, when strong sunlight and hot weather make ground-level ozone a public health concern. MDE says pollution transported into Maryland can account for about 70% of pollutant levels during bad air quality episodes, which helps explain why Baltimore can see alerts even when local sources are not the only cause. The ozone plume is also found along the I-95 corridor, putting commuters and neighborhoods tied to that travel spine in the path of the worst air.

Baltimore’s recent ozone history shows why the alert matters. In the Baltimore, MD nonattainment area, 8-hour ozone concentrations exceeded the 2015 health-based standard on 4 days in 2025 and 11 days in 2024. MDE says unhealthy air days are expected to double in the Baltimore-Washington metro area, based on earlier ozone data from 2003 through 2007.

For the next few days, the safest move is to shift outdoor work, field practices and long walks outside the midday-to-afternoon peak. Seniors and anyone with breathing or heart problems should stay alert to worsening symptoms, and families can reduce exposure by keeping windows closed during the hottest part of the day and checking on older relatives. MDE has tied the warning to Clean Air Month in May and Maryland’s Air Quality Awareness Week, which ran May 4-9, 2026, as it pushes residents to pay closer attention to forecasts when heat and ozone build together.