NYISO Prepares for Heat Dome and Increased Demand on the High Voltage Electric System

RENSSELAER, NY (06/29/2026) (readMedia)-- Rensselaer, NY – A large heat dome will bring extreme temperatures to New York this week and drive up consumer demand on the electric system. When temperatures and humidity spike, increased demand for air conditioning can strain generation and transmission resources.

During extreme heat advisories and potential energy shortages, the New York Independent System Operator (NYISO) actively manages the power grid through a tiered alert system and various grid-reliability measures. The NYISO's System Conditions page can be viewed at www.nyiso.com/system-conditions.

The NYISO may issue grid alerts if energy reserve margins drop below specified levels. These alerts are designed to raise awareness about grid conditions and inform the public if electricity conservation is necessary.

As of Monday, June 29, the forecasted baseline peak demand during the heatwave is as follows:

• Wednesday, July 1: 29,950 MW

• Thursday, July 2: 31,730 MW

• Friday, July 3: 30,010 MW

• Saturday, July 4: 28,270 MW

In July 2013, New York recorded a record peak of 33,956 MW at the end of a week-long heat wave. Peak demand is a measurement of the average total electric demand by consumers for a one-hour period.

NYISO operates the bulk electric system under the nation's strictest reliability standards. System reliability requirements are established, maintained, and enforced by the Federal Energy Regulatory Commission, North American Electric Reliability Corporation, the Northeast Power Coordinating Council, and the New York State Reliability Council.

About the New York ISO

The New York Independent System Operator (NYISO) is a not-for-profit corporation responsible for operating the bulk electricity grid, administering the competitive wholesale electricity markets, conducting comprehensive long-term planning, and advancing the technological infrastructure of the electric system serving the Empire State.