SAN FRANCISCO (KRON) — A frost warning and a freeze warning have been issued for early Monday morning for parts of the San Francisco Bay and Monterey Bay areas, National Weather Service officials said.

Both warnings went into effect at midnight and will last until 8 a.m.

The freeze warning is in effect for the North Bay mountains and valley, East Bay valleys and hills, Santa Clara Valley and interior Monterey County locations such as the Salinas Valley.

Weather officials are predicting lows in the 20s and lower 30s.

The frost warning is in effect for the coastal areas of San Francisco Bay and Monterey Bay areas as well as the shoreline of San Francisco Bay. But it does not include the city of San Francisco, weather officials said.

Lows will generally be in the lower to mid 30s but the temperature in some areas may dip into the upper 20s.