Wales wins 'brief respite' from big freeze
Temperatures rose slightly overnight in Wales, but forecasters warn that the big freeze will return after Sunday.
In coastal parts of Wales, thermometers crept up to 4C (39F) on Saturday morning, as snow was replaced by rain showers.
But inland, many parts have remained at freezing, leading to severe ice problems on roads in Swansea, Carmarthenshire and Ceredigion.
Dyfed-Powys Police are urging motorists not to drive unless necessary.
The force said it had dealt with about 75 road accidents by mid afternoon, due to the ice, though no injuries have been reported.
Officers say stretches of roads badly affected by black ice include the A40 between St Clears and Carmarthen, the A487 between Haverfordwest and Newgale, and all the B roads leading up to Aberystwyth.
Police were forced to close the A484 road between Kidwelly and Uplands Arms in Carmarthenshire due a multiple collision on ice.
The conditions have also hit public transport services in parts of mid, south and west Wales.
More than 30 bus services in Swansea, Neath, Maesteg, Llanelli and Carmarthen were cancelled early on Saturday morning.
In north Wales, fire and rescue teams were called to an incident at Llandudno Junction, Conwy, after an empty bus skidded on black ice and hit a wall. No-one was injured.
Gritting crews have been out overnight throughout Ceredigion, where the council warned that conditions had deteriorated overnight.
A Ceredigion spokesperson added: "Our workforce is doing its best to continue applying rock salt to the primary road network overnight but conditions are getting increasingly treacherous, even for our specialist equipment and experienced drivers."
The weather has also led to a number of events being cancelled over the weekend, with the latest reported casualty being the Helena Tipping 10k race in Wrexham on Sunday.
The British Heart Foundation's Santa Jog in Cardiff and the Torfaen 10K race, also on Sunday have been postponed.
The National Botanic Garden of Wales said it had decided to close to visitors at Llanarthne, Carmarthenshire, because of conditions.
"We havr a lot of snow still on the ground here and the rain fall has turned our main car park into a frozen pond," explained a spokesperson.
"Many paths in the garden are dangerous and some are just impassable. We've gritted where we can but, with more than 600 acres to cover, there's not a lot more we can do."
Staff said they hoped to be able to reopen the grounds on Sunday.
BBC Wales' weather presenter Sue Charles said the rise in temperatures was a "brief respite".
"Saturday morning will feel quite murky, with poor visibility in the hills and outbreaks of rain, sleet and snow spreading eastwards," she said.
"But with more of a south-westerly airflow, it is not as cold, and we could even see 8C (46F) in Swansea.
"Sunday's definitely the brighter day of the weekend - generally cold, dry and sunny.
"But this is just a brief respite with the higher temperatures over the weekend - it is turning colder again next week, with overnight frosts - and no significant thaw."
BBC Wales has the latest online weather updates.