A severe thunderstorm warning has been issued for the Yass district, with damaging winds, large hailstones and heavy rainfall predicted.
The rain may lead to flash flooding over the next several hours.
Yass State Emergency Service (SES) controller Bob Buffington advised people to get rid of light or loose materials, for example throw away any plastic, glass and branches.
He said to secure loose things, for example tie down trampolines, close all doors and windows.
Also have a supply of lights, batteries, at least one radio and gather all precious documents.
Controller Buffington urged residents to listen to the emergency stations. If in or near Yass listen to 666 ABC AM.
If in an emergency situation, call 000.
For emergency damage to property due to the storm call the SES on 132500.
The SES also warned not to walk, ride your bike or drive through flood water.