New York, California Sizzle as Extreme Heat Strains Power Grids

Extreme heat is testing power grids across much of the U.S. on Wednesday, with Washington forecast to top 100F (38C), New York City’s heat index reaching 102F and high temperatures extending into California.

PJM Interconnection has a hot weather alert in effect through Friday as electricity demand climbs across its Mid-Atlantic and Midwest footprint, while New Jersey Transit warned riders that high temperatures could slow trains and cause delays.

“Today is probably the hottest day for New York City,” said Bob Oravec, a senior branch forecaster at the U.S. Weather Prediction Center. “The worst of the heat is today for New York City and today, tomorrow and Friday for DC.”

Large areas of Southern California are also under extreme heat warnings and advisories, the weather service said. Wednesday’s high may reach 95F in downtown Los Angeles.

Wildfire smoke from hundreds of fires burning across Canada continues to blanket parts of the Great Lakes, Midwest and Northeast. Air quality alerts are in effect across portions of the Midwest and Northeast, and forecasters expect some of the smoke to mix closer to the surface across New England and New York City later Wednesday before spreading toward Washington and Philadelphia. People with heart disease, asthma and other respiratory conditions are most at risk from deteriorating air quality.

Meanwhile, the fire threat is rising across California and the West, where dry winds have raised an elevated, or level 1 of 3, threat, the US Storm Prediction Center said. Onshore winds across California will dry out and heat up as they roll downhill across the state’s coastal mountain ranges and Central Valley.

While several small blazes are burning across California, the largest is the Elephant Fire in Sierra County that has consumed 15,526 acres (6,283 hectares) and is 42% contained, the California Department of Forestry and Fire Protection said. The blaze is burning on federal land about 22.8 miles (37 kilometers) northwest of Reno, Nevada.

Heavy rain will continue across central Texas, where more than a foot of rain has fallen in parts of the Hill Country west and north of San Antonio during the past three days. The same region was devastated by floods a year ago that killed at least 160 people. Governor Greg Abbott has declared disasters in 59 counties and ordered emergency operations to remain at an elevated level as additional rounds of rain move through.

In the tropics, Tropical Storm Elida formed in the eastern Pacific about 565 miles (909 kilometers) south-southwest of the southern tip of Baja California. The storm is forecast to strengthen into a Category 2 hurricane by Friday with sustained winds near 100 mph, though it is expected to remain well offshore as it tracks northwest into the Pacific.

Top photo: A New York Police Department (NYPD) traffic officer drinks water during high temperatures in New York, on Friday, July 3, 2026. Bloomberg.