Southern California is experiencing an intense heat wave that has broken multiple temperature records and produced an unprecedented streak of 100-degree days in October. The persistent high-pressure system dominating the region has led to sinking, warming air and limited overnight cooling, exacerbating the extreme conditions.

Meteorologists attribute this heat wave to a combination of factors, including downsloping winds and unusually warm ocean temperatures. These ocean conditions, influenced in part by an ongoing El Niño event, have weakened Southern California’s typical sea breeze, which often serves as a natural cooling mechanism for the area.

The National Weather Service office in Oxnard reported that this marks the fourth consecutive day with temperatures at or above 100 degrees in downtown Los Angeles, a feat rarely seen in October since records began in the late 19th century. Historically, the average number of 100-degree days in downtown Los Angeles in October has been close to zero. Currently, the city is tied with the years 1958 and 1971 for the highest number of such days in the month, and forecasters say there is a chance that record will be surpassed if temperatures reach 100 degrees on Tuesday.

“We have heat events in October, but this streak of 100-plus degree days is becoming notable,” said Rose Schoenfeld, a meteorologist with the National Weather Service. The ongoing heat wave has already set new daily records across the Southland, with downtown Los Angeles registering a record-breaking high on Monday.

Forecasters expect the high temperatures to continue for several more days as the high-pressure system remains anchored over the region. The sustained warmth poses potential impacts to public health and energy demand as the season typically ushers in cooler temperatures in Southern California.