US Northeast Braces for Intense Heat Wave, Cooling Centres Open Ahead of July 4

A multiday heat wave is gripping the US Northeast , with New York, Boston and Philadelphia under heat warnings ahead of Independence Day celebrations. Temperatures are expected to reach the high 90s°F (mid-to-high 30s°C) , while Boston and Philadelphia could exceed 100°F (38°C) . High humidity is forecast to make conditions feel even hotter.

The extreme weather is being driven by a heat dome, a high-pressure system that traps hot air and humidity near the surface. Scientists say climate change is increasing the frequency and intensity of such heat waves by raising average temperatures and atmospheric moisture.

The scorching conditions coincide with Fourth of July events, including parades, fireworks, concerts and other outdoor celebrations expected to draw large crowds.

New York City Mayor Zohran Mamdani urged residents to avoid prolonged exposure to the heat, warning that triple-digit temperatures pose serious health risks. Medical experts cautioned that high heat combined with humidity can lead to heat exhaustion and heat stroke , particularly among older adults, children, outdoor workers and those with existing health conditions.

Experts also warned that cities experience the urban heat island effect , where concrete and asphalt absorb and retain heat, making urban areas hotter than surrounding regions.

Authorities have opened hundreds of cooling centres , deployed outreach teams to assist vulnerable residents and issued advisories urging people to stay hydrated, wear light clothing, avoid strenuous outdoor activities during peak afternoon hours, check on elderly neighbours and never leave children or pets inside parked vehicles.