SAN DIEGO — John Larson sat on a blanket on a Southern California beach, furiously posting videos on Facebook of his sons jumping in the waves and bracing for the expletives from friends in Buffalo, N.Y.

It was 5 below zero when Larson and his sons left this weekend for their trip to San Diego, where a heat wave sent temperatures into the mid-80s on Tuesday.

‘‘Oh yeah, they hate me,’’ the 51-year-old graphic designer said of the response he got to his beach posts.

Beaches in Southern California were crowded after the holiday weekend saw record-breaking heat from Los Angeles to San Diego, while the East Coast and the South cleaned up from a deep freeze and tornadoes.

It was even hotter in Phoenix. The National Weather Service forecast a high of 90 degrees Tuesday, which would be the earliest 90-degree day on record for the desert city.

The normal temperature for this time of year is in the 70s. The previous mark was set 30 years ago, on Feb. 24, 1986.

Phoenix also saw record highs last week as an unusually strong high-pressure system lingered.

The surge in temperatures has been bringing rattlesnakes out of hibernation. A fire agency in southern Arizona started getting calls in the last two weeks from panicked residents about the poisonous snakes in their yards and on their patios, something they don’t usually see until late March.

Millions along the East Coast, meanwhile, were still shivering from freezing temperatures.

A treacherous mix of snow, sleet, and freezing rain caused car crashes from the Mid-Atlantic states through Pennsylvania to northern New England on Tuesday.

At least three deaths were reported on slick roads, all in Virginia, and thousands were left without power from weather-caused outages.

Associated Press