DEP issues air-quality warning for Sunday as heat wave begins

A heat wave is expected to last through at least next Monday, with temperatures in the mid 80s to low 90s and high ozone formation expected during some of that time.

The fountain in Franklin Square is likely to be a popular gathering spot in the week ahead as the region experiences a heat wave.Read moreTIM TAI

by Diane Mastrull

Published Jun. 16, 2018, 5:40 p.m. ET

Sunday should not be the day you decide to run a marathon or engage in a rigorous hike.

Father's Day will mark the start of a stretch of particularly hot and sticky days in the region, with high temperatures in the mid 80s to low 90s through at least next Monday and periods of high ozone formation.

As such, the Pennsylvania Department of Environmental Protection on Saturday issued a "code orange" air-quality action day for Philadelphia, Bucks, Chester, Montgomery and Delaware Counties. Under the U.S. Environmental Protection Agency's color-coded standardized air-quality index, orange signifies unhealthy pollution levels for young children, the elderly, and those with respiratory problems such as asthma, emphysema, and bronchitis.

For those individuals, limited outdoor activities are recommended. Orange is the most serious of three air-quality levels.

The DEP, in conjunction with the Air Quality Partnerships for the Delaware Valley, said ozone formation will be "highly favorable" into Monday due to a strong ridge of high pressure, a mostly sunny sky, temperatures in the low to mid 90s, and winds from the west to southwest. An approaching cold front, likely to bring afternoon and evening thunderstorms Tuesday, will reduce the risk for elevated ozone, according to the DEP announcement.

You can help keep the air healthy through the heat wave by refueling cars and trucks after dusk, setting air-conditioner thermostats to a higher temperature, carpooling or using public transportation, and combining errands to reduce trips, the DEP said.