Amid sweltering Labor Day heat across much of Southern California, Lancaster on Monday marked its 58th day this year with temperatures above 100 degrees — breaking a record set 18 years ago.

It was 104 degrees at General William J. Fox Field, the National Weather Service said. The old record at the Lancaster airport, set in 2003, was for 57 days above 100 degrees.

Meanwhile, the Antelope Valley, including Lancaster and Palmdale, will likely see high temperatures of up to 108 degrees through 8 p.m. Wednesday, according to the National Weather Service.

The weather service announced Monday as part of its excessive heat warning that the “dangerous hot conditions” will “significantly increase the potential for heat related illnesses,” especially for people who are outdoors.

An excessive heat warning is issued 12 to 24 hours before “extremely dangerous heat conditions begin,” according to the National Oceanic and Atmospheric Administration, which oversees the NWS, though on Monday, high temperatures were already present near Lancaster.

Representatives for the NWS and NOAA did not return requests for more information about the new Lancaster record Monday. But on its website, NOAA noted that climate change can “create or intensify extreme heat.”

“This trend is expected to continue with climate change driving more hot days, more compound events — which are multiple extreme events occurring simultaneously or successively and/or underlying conditions that amplify extreme event(s) — such as concurrent heat waves and droughts, and more extreme heat conditions in cities,” NOAA said.