Bitterly cold conditions have swept across the UK with large parts of the country lashed by icy winds and snow.

The UK could see its coldest temperatures of the winter in the next 36 hours, with 15cm (6in) of snow on higher ground and gales in the north-east.

Snow affected most of the UK on Saturday and the Met Office has issued weather warnings for all English regions bar the south-west, warning of more inclement weather through the night and until 3pm on Sunday. It said ice and snow could cause problems for travellers although most routes seemed to have escaped serious disruption during the day on Saturday.

Health officials have warned older and sick people to stock up on essential medicines and food ahead of the cold weather.

Conditions could beat the current lowest temperature of the winter so far, the -11C (12.2F) recorded at Cromdale in Moray, north-east Scotland, on 5 December.

A Met Office spokesman said: “Outbreaks of sleet and snow will continue during Saturday but generally becoming confined to higher ground through the afternoon, with only a low risk of disruption. However, during Sunday, an area of more widespread and at times heavy snow [rain or sleet at lower levels] is expected to develop along the Pennine chain, with drifting of snow in the strong northeasterly winds.”

The cold winds from northern Europe are expected to bring sleet and snow to other eastern areas, but it is unlikely to settle. Overnight into Saturday there will be widespread frosts, particularly in the west, where there will be clearer skies. The biting wind at the weekend will leave temperatures feeling much colder.

Temperatures in the UK ranged between 3C and 5C on Saturday afternoon, hitting 6C in Belfast.

Public Health England has issued a warning amid the plummeting temperatures. Prof Paul Cosford, medical director, said: “With more cold weather across all parts of England, now is the time to really think how it could impact you and your family, particularly those who are very young, over 65 or who have heart and lung conditions.

“Try to keep homes heated to at least 18C (64F), stock up on any essential medicine or food that you need before the cold arrives and remember that you will be warmer wearing several thin layers instead of fewer thick ones.”

Temperatures are expected to rise after the weekend, hotting up in time for Valentine’s Day, when the mercury is forecast to hit double figures in London and other parts of the south-east.