Councils across Wales are making plans for icy roads and up to 20cm of snow which is forecast for Friday.
The Met Office has a yellow "be aware" warning in force from 00:05 GMT on Friday to 18:00 on Saturday.
Counties across the north of Wales are expected to be worst affected, with the heaviest snow showers.
Icy road surfaces, delays in rail or air travel and the interruption of power supplies in some rural areas are also anticipated.
Dwr Cymru warned customers their pipes could freeze or burst when temperatures fall, costing thousands of pounds worth of damage.
It is offering free lagging kits - warm coverings around the outside of exposed pipes - to customers to protect pipework.
Details of any school closures are available on most council's websites and social media. Anglesey council said schools would contact parents directly in the event of closures.
Denbighshire council said it was prepared for the wintry weather with salt stocks at its three depots and its highways team geared up to work around the clock to keep the main A and B roads and roads connecting villages open.
Conwy council said it was "well prepared for winter weather", with 11,000 tonnes of rock salt in stock and a fleet of 13 gritting lorries working out of three depots.
Gwynedd council said whenever snow or ice was predicted, priority routes were pre-treated with salt and grit.
Anglesey council said its gritters would be out on Thursday evening and the early hours of Friday and will remain on standby.
Rhondda Cynon Taf council said it was "prepared for what the winter weather might bring" and had a dedicated workforce that was able to carry out emergency work in the middle of the night to avoid disruption.