Dangerous heat, poor air quality expected on Long Island this week

An extreme heat warning is in effect for Long Island from noon Wednesday through 9 p.m. Friday, with dangerously hot and humid conditions expected to push heat index values as high as 110, according to the National Weather Service in Upton.

The warning covers Suffolk and Nassau counties, including Riverhead and the East End. Forecasters said the hottest conditions are expected Thursday and Friday afternoons.

“This has potential to be a multi-day extreme heat event with near-record high temperatures and little overnight relief,” the weather service said. “This level of heat can be deadly for those without adequate cooling and hydration.”

The heat is part of a larger dome of high pressure expanding across the central and eastern United States this week, bringing some of the hottest conditions of the summer so far to many areas, according to AccuWeather. The National Weather Service said the prolonged heat could also strain infrastructure, with potential impacts to transportation and electrical and water systems.

An air quality health advisory for ground-level ozone is also in effect Wednesday for Nassau and Suffolk counties, according to the New York State Department of Environmental Conservation.

The air quality advisory runs from 11 a.m. to 11 p.m. Wednesday. Outdoor air quality is forecast to exceed an air quality index value of 100 for ground-level ozone, state officials said.

The advisory comes as a prolonged stretch of hot, humid weather builds into the region. In Riverhead, the National Weather Service forecast calls for a high near 90 on Wednesday, then climbing to about 96 Thursday and 97 Friday. Overnight lows are expected to remain elevated — around 72 Wednesday night and 75 Thursday night — limiting relief from the heat.

An extreme heat watch is also posted from Friday evening through Saturday evening, signaling the potential for dangerous heat to continue into the weekend.

The National Weather Service urged residents to take precautions, especially those who work or spend time outdoors. Officials recommend rescheduling strenuous activity to early morning or evening when possible, wearing lightweight, loose-fitting clothing and drinking plenty of water.

Seniors and people with chronic health problems or mental health conditions are at increased risk, the weather service said, noting that homes without air conditioning can be much hotter than outdoor temperatures. Residents are encouraged to use air conditioning or seek out cooled indoor spaces, and to check on vulnerable friends, family members and neighbors.

Southold Town will open a cooling center Thursday and Friday from 8 a.m. to 4 p.m. both days at the Southold Town Community Center, Room 1, located at 1170 Peconic Lane, Peconic, Southold Town Supervisor Al Krupski annouced Tuesday morning.

When pollution levels are elevated, the New York State Department of Health recommends limiting strenuous outdoor physical activity to reduce the risk of adverse health effects. Those who may be especially sensitive include young children and people with preexisting respiratory problems such as asthma or heart disease. Anyone experiencing symptoms should consider consulting a physician.

For outdoor work, the Occupational Safety and Health Administration recommends frequent rest breaks in shaded or air-conditioned areas. Anyone overcome by heat should be moved to a cooler location. Heat stroke is an emergency — call 911.

Forecasters also noted a chance for isolated to scattered thunderstorms at times Wednesday through Saturday, particularly in the afternoon and evening, though timing and coverage remain uncertain. AccuWeather said thunderstorms riding along the northern edge of the heat may become strong in parts of the region, with the potential for damaging wind gusts in some areas.

For more information about air quality conditions, visit the state DEC’s air quality website at https://on.ny.gov/nyaqi or call the air quality hotline at 1-800-535-1345.