SAN DIEGO (FOX 5/KUSI) — Bundle up and cover those plants, it will be cold again tonight. Overnight temperatures will reach into the upper 30s in some areas of Southern California on Super Bowl Sunday.

The National Weather Service (NWS) has issued a frost advisory for valley areas in San Diego, San Bernardino and Riverside counties and the Inland Empire through 8 a.m. Monday.

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If you’ve been feeling cold the past few days, it’s not just you. Overnight temperatures have been getting gradually colder leading up to Sunday, ensuring us in Southern California are breaking out those coats.

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The advisory goes into effect at 11 p.m. Sunday for the cities of Riverside, San Bernardino, Ontario, Moreno Valley, Fontana, Rancho Cucamonga, Corona, Escondido, El Cajon, San Marcos, La Mesa, Santee and Poway, according to NWS.

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The coldest areas are expected to be between Perris and Temecula, in portions of San Diego County valleys, and near the San Pasqual Valley and Ramona.

When temperatures dip into freezing, its important to cover outdoor plants and to take steps to keep pipes from freezing.

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