An extreme heat watch is in effect for parts of Southern California from Tuesday morning through Friday evening, with the National Weather Service warning that temperatures could reach dangerous levels across several inland and desert locations.

The NWS Los Angeles and Oxnard office said a heat advisory would run from Sunday morning through Tuesday morning in many coastal, valley and mountain areas. The same notice carries an extreme heat watch for Tuesday through Friday evening.

Temperatures of up to 112 degrees are possible in the Antelope Valley and nearby foothills. The notice lists lower but still hazardous possibilities for other areas, including up to 107 in portions of southwest California and up to 100 in coastal and inland Los Angeles County locations.

MyNewsLA reported that downtown Los Angeles reached 97 degrees on Saturday and that temperatures exceeded 100 in parts of the San Fernando, Santa Clarita and Antelope valleys. The report said forecasters expected the heat to peak between Tuesday and Thursday, while warm overnight conditions could continue.

The NWS says heat-related illness becomes more likely during the event. Its public guidance includes drinking plenty of fluids, staying in air-conditioned rooms, avoiding the sun during the hottest period and checking on relatives and neighbors. The agency also links the prolonged heat to elevated wildfire danger in some areas.