A major early-season hot spell gripped the West Coast to start the week. It’s delivering widespread record heat, and more came Tuesday.

The epicenter of broiling conditions is California, where records have fallen from south to north. San Francisco Airport soared to a record high of 100 degrees Monday, which is its earliest instance hitting the mark and its hottest June temperature, by two degrees.

About 45 million people are under a heat advisory or excessive heat warning for a third straight day Tuesday because of an unusually strong area of high pressure lodged over the region.

June is often a month where the wind blows off the cool ocean into coastal areas while scorching heat is confined to the interior valleys. But, at the moment, a strong high pressure system is keeping the clammy maritime air out to sea while the scorching sun bakes land areas, even along the coast

Under mostly sunny skies, record highs started falling in California Sunday. Among the records, Riverside hit 104 degrees and Burbank tied its record of 100 degrees. Records also fell in the Bay Area and Central Valley. San Francisco Airport’s 92 degrees broke a record, as did Salinas, soaring to 98.

On Monday, Thermal — a desert location to the northeast of San Diego — reached 113 degrees, besting a record of 111 for the date. El Cajon crushed its previous daily record of 94 degrees with a high of 104 degrees. A number of records were demolished in the Bay Area as well, such as 107 degrees in King City and 105 degrees in Salinas.

San Francisco Airport’s 100-degree reading Monday tied for the fifth-hottest reading there since the mid-1940s and the hottest of any summer month (June through August). Notably, every other 100-degree or hotter day has come in September, when offshore winds (rather than winds off the ocean) are more prevalent.

Monterey also posted its highest June temperature Monday soaring to 97 degrees. That’s the warmest reading between June and August, as well, and third highest in any month behind 98 and 103 degrees in early September 2017.

Heat has been making life uncomfortable, especially in coastal cities that rely on nature’s air conditioning to keep cool.

Widespread power outages occurred near San Francisco Monday, although officials have not yet attributed them to the heat. Bay Area Rapid Transit also reported significant delays as a result of the weather. Fire danger is high, and air quality is poor.

The core of the heat shifts northward as it eases through midweek. By Wednesday, the hottest weather relative to normal should be focused in the Pacific Northwest, where record highs are possible in Oregon while temperatures are expected to hit the mid-80s in Seattle.

Into the future, this round of high heat does ease, but indications are that the hot high pressure will attempt to become reestablished later this month. As such, additional heat spells seem likely.