Antonio Seda wasn’t taking any chances when it came to securing prime beach real estate for a sweltering Independence Day.

The Southbridge, Massachusetts, resident staked out his family’s spot on Old Orchard Beach – partly shaded by the iconic pier but also partly in the sunshine – at 6 a.m. Wednesday. Eight hours later as locals and tourists continued to pack the beach in search of relief from the heat, Seda was lazily swinging in a well-shaded hammock strung between pilings while partner Marilyn Morales and their three girls relaxed nearby.

“I like it,” Morales as she scanned the crowded horizon of one of Maine’s most popular beaches. “It’s a good family place. And it’s a nice atmosphere.”

The Fourth of July is always a beach day for many in Maine, weather permitting. And Wednesday’s weather – with record temperatures in Portland – made a beach trip practically a necessity for some.

“This is pretty packed,” said Tom Pelletier from nearby Saco, who added he’s been frequenting Old Orchard every chance he gets since a child. Like Seda and Morales, Pelletier and Tayla Savage set up near the shade but close to the water and, importantly, the 99-cent hot dogs on the pier above. “I’ve only seen it like this a couple of times.”

Maine, like much of the U.S., was in the grips of a massive heat wave.

The mercury hit 93 degrees in Portland between 4 and 5 p.m., surpassing the day’s previous record of 90 degrees, set in 2010, according to the National Weather Service. Conditions were similarly hot or hotter inland. Bangor and Millinocket were both reporting readings of 93 degrees at 5 p.m. while a sea breeze was bringing temperatures along the coast back down into the upper 80s.

Central Maine Power reported a few scattered outages Wednesday because of the “load” on the power grid, but attributed a larger outage that temporarily affected about 4,500 customers in Waldo County to a transmission line problem.

The holiday allowed many residents without air conditioning to search out places to cool down. But it also meant some of the easiest public options for those on a budget or with limited traveling abilities  — such as libraries — were closed for the day.

In Portland, city officials opened the Kiwanis Community Pool on Wednesday from 1:30 to 4:30 p.m. and extended the hours at the Kiwanis pool splash pad from 8 a.m. to 8 p.m.

South Portland’s Maine Mall became a refuge, of sorts, for others.

Unfortunately, conditions will likely be just as hot – but even stickier – around much of Maine on Thursday.

The National Weather Service has issued a heat advisory for all of the southern coast to the Rockland area as well as parts of western, central and northern Maine. A heat advisory means the combination of heat and humidity – with temperatures in the lower- to mid-90s and dewpoints around 70 degrees – increases the risk of heat-related illness.

Meteorologist Eric Schwibs with the National Weather Service’s Gray office said a dewpoint of 70 is considered “oppressive” and is more akin to the humidity levels one might find in the deep South or along the Gulf Coast.

“Tomorrow we are going to fry,” Schwibs said. “It is going to be another hot one.”

The weather service had also issued a “coastal hazard message” for some areas on Wednesday warning beachgoers that it’s still possible to get dangerously cold in the water. While ocean temperatures along the southernmost Maine coast were in the 70s, they were still in the upper 50s or low 60s in the midcoast and Penobscot Bay.

“The warm air temperatures in the 80s may cause people to underestimate the dangers of the cold water temperatures which are currently only in the upper 50s,” the advisory reads. “The cold water temperatures can quickly cause hypothermia to anyone immersed in the water. Anyone on boats or paddlecraft should use caution to avoid this threat.”

Back at Old Orchard, both the sandy beach and the water were filled with people and red-white-and-blue paraphernalia of all types on Wednesday afternoon.

Brian and Deb Albertelli of Rochester, N.H., had made what’s become an annual trip to Old Orchard with their two grandchildren, ages 2 years and 8 months. Although only about an hour away, it’s a different scene than New Hampshire, they said, and the couple convinced friends Robert Russell and Jeanine Carter of Farmington, N.H., to join them this year.

But they had also staked out a spot on the edge of the sun but right to the shade of the pier so their youngest grandchild, age 8 months, could stay out of the sun. This group didn’t seem to mind the heat or the crowds, however.

“We got here at 8:30 this morning” Brian Albertelli said. “You have to get here early to get this spot.”

Old Orchard Beach is jammed with visitors on a record-setting hot Fourth of July on Wednesday. Jill Brady/Portland Press Herald)