PJM Issues Hot Weather Alerts Through June 24


PJM has issued Hot Weather Alerts for the Mid-Atlantic transmission zone between June 22 and June 24 and for the Dominion transmission zone on June 23.

Hot Weather Alerts are issued when temperatures are expected to exceed 90 degrees Fahrenheit with high humidity, driving up demand for electricity.

Across PJM’s footprint of 13 states and Washington, D.C., current load forecasts project the entire peak load to range between an estimated 128,000 MW to 130,000 MW through June 24.

What Is a Hot Weather Alert?

Reliable electricity service is PJM’s priority. By coordinating with its members to ensure that power flows where and when it is needed, PJM is ready to meet summer demand for the 65 million customers in the areas it serves. 

A Hot Weather Alert prepares transmission or generation facilities for extreme hot or humid conditions which may pose capacity issues for the grid. To reliably serve demand, transmission and generation operators determine whether maintenance or testing may be deferred or canceled. PJM’s reserve resources are available to cover for generation that may be unexpectedly unavailable or to help meet demand that is higher than forecasted.

Summer Preparedness

This summer, power system operators at PJM are prepared to serve a forecasted summer peak demand for electricity of approximately 148,000 MW.

It remains unknown how the continuing pandemic will affect peak load this summer as air conditioning usage evolves among residential, commercial and industrial customers. Thus far, pandemic-related social restrictions have driven down electricity use, with closures of commercial, industrial and institutional power users more than offsetting the increased electricity use by people working from home. Electricity demand in recent weeks has moved closer to levels expected for the time of year and the weather as businesses reopen, and people use their air conditioners throughout the day while working from home.

Last summer’s peak demand measured more than 151,000 MW on July 19. One megawatt can power approximately 800 homes. Track PJM’s markets and operations in real time on the Markets and Operations page on PJM.com or through the PJM Now app for iPhone and Android. Learn more about how PJM prepares for summer operations on the Learning Center.