NYC's First Heatwave of 2025: What You Need to Know

New York City is bracing for its first heatwave of 2025, arriving next week with temperatures soaring into the 90s. This article will cover everything you need to know about heatwaves in NYC, and how to stay safe.

What is a Heatwave?

A heatwave is defined as three or more consecutive days with temperatures of 90 degrees Fahrenheit or higher. NYC averages two heatwaves per summer, but climate projections suggest this could increase to 69 by the 2050s.

<img src="https://assets1.cbsnewsstatic.com/hub/i/r/2025/06/19/60051605-e1c1-4316-ab36-8ba87f80da4d/thumbnail/640x360/86f806776706c341473bc77670c38c99/jl-heat-wave-definition.png?v=64f55bb7ef9382fe7916b907da543f1f" alt="Definition of a heatwave">

Heatwave Dangers

Heat is the number one weather-related killer in the US. In NYC, 370 deaths are attributed to heat annually, with the South Bronx, Upper Manhattan, and Central Brooklyn being the most vulnerable areas due to factors like socioeconomic status and lack of air conditioning.

The Urban Heat Island Effect worsens the situation, trapping heat at night and creating a significant temperature difference between the city and suburbs.

Heatwave vs. Heat Dome

Many heatwaves are caused by heat domes, high-pressure systems that trap hot air and humidity, potentially leading to poor air quality.

<img src="https://assets1.cbsnewsstatic.com/hub/i/r/2025/06/19/8c5c961e-99e7-4d7b-be22-f8a0f624256d/thumbnail/640x360/ce720f18f8cc1e19753f6a53be88e698/jl-heat-dome-1.png?v=64f55bb7ef9382fe7916b907da543f1f" alt="Image explaining heat domes">

Excessive Heat Warnings & Heat Advisories

Excessive heat warnings are issued 24 hours in advance of forecasted heat indices of 105 degrees or higher for at least two consecutive hours. These warnings indicate a need for extreme caution, including staying indoors, staying hydrated, and avoiding strenuous activity.

<img src="https://assets3.cbsnewsstatic.com/hub/i/r/2025/06/19/375dc27a-f9ca-4a94-afa5-188daaf1ba10/thumbnail/640x360/62e17dce5c86185cedf7f611770f9d5c/jl-fa-heat-safety-awareness-week-1.png?v=64f55bb7ef9382fe7916b907da543f1f" alt="Heat safety tips">

Find a cooling center near you: https://finder.nyc.gov/coolingcenters/