The metro area is on track for record-breaking heat, and it’s only May.

The heat wave buckled pavement and sent people into malls and movie theaters to keep cool. It lasted all weekend and shows no sign of cooling down for Memorial Day or early this week.

By Sunday, every metro-area county had issued a heat advisory, with the National Weather Service (NWS) upgrading those warnings Sunday afternoon to “excessive heat watch” status through Monday night.

Twenty-six counties around the state posted heat advisories until Monday night as well.

“We just notched our 4th consecutive 90 degree day, tying the record for longest stretch of 90s in May,” the NWS tweeted Sunday morning.

That four-day record was set in 1874, 1934 and 1988. The state has a solid chance at breaking it Monday, said NWS meteorologist Chris O’Brien.

“It’s very interesting and unusual,” he said of the weather. “It shows what’s possible, that it can get this warm in May.”

Some libraries, recreation centers, malls and Salvation Army buildings are designated cooling centers, offering an escape to those who need it. Hennepin County offers a map of all of the places to chill out across the metro, but officials there recommend calling the phone numbers listed to see if they are open Monday.

Libraries, for instance, are closed on the holiday.

The Mall of America saw higher-than-usual traffic this weekend. Many of the visitors were families, said mall spokesman Dan Jasper: “Part of it was the heat, people just looking for a place where it was not so hot.”

Movie theaters were also busier than usual.

Monday may also set records for the hottest Memorial Day. The record of 95 degrees was set in 1939, O’Brien said. “Looks like we’ll have a good shot at [beating] that,” he said.

While warm weather is ideal for some traditional Memorial Day weekend activities like boating, fishing and swimming, some groups are especially vulnerable to the scorching heat.

“In a normal year, about 175 Americans die of complications from overheating,” warned Hennepin County’s website. “Young children, senior citizens and people who are sick or overweight are most vulnerable.”

Hot days can be as challenging for homeless people as frigid days in the winter, said Tracy Berglund, Catholic Charities’ senior director of housing stability. During extreme temperatures, the organizations’ two day shelters fill up more quickly, she said, adding that high temperatures are especially hard on homeless people over 55.

Metro-area temperatures will likely inch toward 100 Monday, with numbers expected to stay in the 90s across the rest of the state.

Thunderstorms may offer a break from the worst heat on Monday evening, Tuesday and Wednesday — but it still will be hot. Highs in the 80s or low 90s are expected Tuesday and Wednesday, according to the NWS.

The simmering air, along with sunshine and light winds, pose a hazard for people sensitive to pollution. The NWS has issued an air quality alert for 24 Minnesota counties, including all seven in the metro area. That alert lasts until 8 p.m. Monday.

Groups that are more susceptible to breathing problems include those with asthma or chronic pulmonary disease, chronic bronchitis and emphysema, along with children and teenagers.