If your air-conditioning isn’t up and running yet, now might be a good time.

Forecasts project a heatwave this weekend that could continue into next week, with max temperatures in the 90’s, according to a weather update from the National Oceanic and Atmospheric Administration.

More pressingly, the heat index — what the temperature actually feels like — could rise as high as 103 degrees Fahrenheit on Sunday, July 1, due to humidity.

“Extreme heat can cause illness and death among the at-risk population who can not stay cool,” the agency noted. “Seniors, infants, and those with chronic health problems or mental health conditions are at an increased risk from the heat.”

High temperatures will mostly affect interior Southern Connecticut, New York City, the lower Hudson Valley, and Northeast New Jersey.

“There is already a Heat Advisory in effect for New York City, Northeast New Jersey, the Lower Hudson Valley and Nassau County NY for Saturday starting at 12 p.m.,” the agency noted.