SAN ANTONIO — The National Weather Service issued a freeze warning for Austin, San Antonio and the surrounding areas between 12 a.m. and 9 a.m. Friday morning.

SLIDESHOW: Snow falls in Central Texas 

Temperatures may drop to between 25 32 degree.

Low temperatures may cause wet spots on roadways to freeze Thursday night, resulting in black ice on bridges, overpasses, and some secondary roadways.

Before a freeze hits, take these precautions:

• Wrap all exposed pipes located outside or in unheated areas of the home.

• Remove garden hoses from outside faucets.

• Cover vents around the foundation of your home.

• Know where your property owner’s cut-off valve is located and how to use it. It should be located adjacent to the water meter box under a 6" metal lid.

During a freeze

• Drip outside faucets 24 hours a day. This is not necessary unless temperatures are expected to be 28 degrees or below for at least 4 hours. 

• Open cabinet doors under sinks adjacent to outside walls.

• In unheated garages, shut off water to washing machines. Water softeners should be drained and protected from freezing temperatures.

• In sustained sub-freezing weather, let water drip slowly from inside faucets.

•Take extra precautions to protect pipes that have frozen in the past.