We wouldn't blame you if you completely lost track of the calendar this weekend.

It will feel like mid-July instead of mid-March, that much seems certain. The National Weather Service says the temperature gauge will reach above the 90-degree mark in parts of the Los Angeles Basin, in local valleys and even along some parts of our coastline.

“We will probably will break some records along the coast and in the valleys,” says NWS weather specialist Bonnie Bartling.

You can blame a high-pressure system moving over our region as we speak. In fact, Bartling told us, the warm-up will start today and will bring above-normal temperatures to Southern California through Monday.

The system will push heat and winds offshore — from the mountains to the sea, according to the service. That means it could be as warm at the beach as it is inland, because our cool Pacific breezes will be fended off by the oncoming warmth.

“The coast will be toasty,” Bartling said.

Credit: NWS/NOAA

Credit: NWS/NOAA

Even overnight low temps will be amazingly out-of-season Saturday and Sunday, she said, with a range of the upper 50s to the … mid 60s!

This could be bad news if you're participating in the sold-out L.A. Marathon Sunday. Bartling noted that a warmer low temperature allows a day to heat up much earlier.

Marathon organizers have moved up the start from 7:25 a.m. to 6:55 a.m. as a result of concerns about how the “record heat” will affect runners.

Lifeguards probably will be busy, too. But it looks as if they'll luck out with relatively small, 1- to 3-foot surf and thus lower chances that life-snatching riptides will greet the throngs who head to the beach for relief.

Remember, however, that the coast won't be much cooler. And note that the Pacific has been relatively warm this winter, with local water temps ranging from 61 to 64 degrees.

Credit: NWS

Credit: NWS

The weather service is warning folks, particularly the elderly, to be prepared for utter hotness:

This is a very early heat wave with the potential to break many record high temperatures starting Saturday. March heat waves can be deadly in the sense that people are not prepared or acclimated for hot weather at this time of year. It is much easier to experience sunburn and/or heat stress due to the higher sun angle and longer daylight.

Bartling says winter's not over just yet. We have until April 30 to wrap up our rain season. Wet and cool weather still have time to return.

By midweek, in fact, things should be closer to normal. A low-pressure system is expected to move in from the coast and give us a sea-breeze-driven cool-down.

By that time the calendar will feel more accurate. Spring arrives on March 20.

Send feedback and tips to the author. Follow Dennis Romero on Twitter at @dennisjromero. Follow L.A. Weekly News on Twitter at @laweeklynews.

Advertising disclosure: We may receive compensation for some of the links in our stories. Thank you for supporting LA Weekly and our advertisers.