Frost advisories are in effect for the mountains, valleys and some coastal areas until 9 a.m. Thursday.

The National Weather Service says the temperature dipped to 14 degrees in the high desert town of Lancaster Thursday morning, breaking a 2006 record low for the date. Neighboring Palmdale had 21.

Many other areas reported lows in the 30s and 40s. Los Angeles and San Diego hit 43.

Forecasters say a slight warming trend is expected later in the day through Friday, with Los Angeles and many other areas seeing highs in the 60s. The region will have a chance of some rain over the weekend.