Boston officially hits 103 degrees; DCR warns of high bacterial count at 3 beaches

By Amanda Cedrone, Ben Wolford and Jaime Lutz, Globe Correspondents

It’s official.

Temperatures in Boston reached 103 degrees at 3:52 p.m. today, matching the record set for this date in 1926, said Alan Dunham, a meteorologist with the National Weather Service in Taunton.

Dunham does not expect the temperature to rise any more today, meaning the all-time record of 104 degrees set on July 4, 1911 will remain intact.

Also this afternoon, the state Department of Conservation and Recreation announced that high bacterial counts have been discovered at King’s Beach in Lynn, one part of Nahant Beach, and at Revere Beach.

“Routinely taken water samples from multiple areas of these beaches all returned with approximately three times the bacteria count determined to be safe by Department of Public Health marine regulations,’’ the DCR said in a statement. “Swimming in water with bacteria counts above normal can cause illness.’’

The DCR is warning people about the test results and is recommending that people to stay out of the water at those three North Shore beaches. In Nahant, the DCR said the beach north of Ward boathouse remains open and “safe for swimming.’’

Since today will be the third straight day with temperatures over 90 degrees, Massachusetts is now officially in its first heat wave of the summer.

New England is drawing near-record amounts of power, and ISO New England pushing nearer to its generating capacity, but so far it is still short of issuing calls to conserve. There is enough power for now.

“Conditions are extremely tight,” said Dominic Slowey, a spokesman for the regional energy operator. “We’re watching the system closely. At the moment we’re OK, but as the heat wave continues, it puts stress on all of the equipment. ... The situation could change on a dime.”

On a typical summer day, he said, consumption is around 22,000 or 23,000 megawatts, with each megawatt being generally enough to power 1,000 homes. The system tops out around 32,000 megawatts if all power plants are online and transmitters are running smoothly, Slowey said.

Boston Emergency Medical Services is handling more calls than normal today, something they’re attributing to the soaring temperature in the city.

“In general our call volume is up,” said Jennifer Mehigan, a Boston EMS spokeswoman. “Wednesday looked about average. Yesterday was up about 12 percent, with an increase in calls in the afternoon.”

An average day sees 300 calls, but by 1 p.m. today, they had already handled 200.

“We haven’t seen anything really serious,” Mehigan said. “Knock on wood.”

For six Massachusetts counties, including Suffolk, the National Weather Service issued an excessive heat warning from noon to 6 p.m.

Because of this, children, seniors, and anyone doing strenuous physical activities should take extra precautions to stay cool and well-hydrated to avoid heat illnesses.

The DCR, the City of Boston, and many other municipalities have extended pool hours or opened cooling centers. Boston has extended the the operation of cooling centers until Saturday night.

People can learn about the facilities available in their communities by calling 211, officials said.

After today, the worst is over. Tonight will see lows in the low to mid 70s – still uncomfortable, Dunham said, but better than the lows of close to 80 degrees last night.

 Temperatures tomorrow, he added, will be “only” in the upper 90s.

 “Humidity will slowly – slowly – be coming down,” Dunham said. “Tomorrow will be uncomfortable also – but today is the worst.”

 On Sunday, the heat wave ends. Expect “highs in the refreshing lower 80s – or, it might even be better, with highs in the upper 70s,” Dunham said.

 And after a week that was light on precipitation, Monday night has a 50 percent chance of showers, which might continue into Tuesday morning, Dunham said.