Easter Sunday has been confirmed as the coldest Easter day on record, with the lowest temperature recorded as -12.5C in Braemar, in the Scottish Highlands.
The previous coldest Easter day since modern records began in 1960 was Easter Monday in 1986, which dipped to -9.8C, the Met Office said.
Average temperatures for this time of year are between 10C and 13C.
The prolonged cold spell covering the UK could last until mid-April, forecasters say.
Easter Monday is expected to remain very cold.
Easter itself is a moveable celebration which falls on the Sunday after the spring full moon, and can fall anywhere between 22 March and 25 April.
Only about 22% of Easters fall in March, a Met Office spokesman said.
The Easter record comes after the entire month of March was provisionally declared the coldest since 1962 in the UK.
The Met Office said that from 1 March to 26 March the UK mean temperature was 2.5C, which is three degrees below the long-term average.
Looking at individual nations, March 2013 is likely to be the fourth coldest on record for England, joint third coldest for Wales, joint eighth coldest for Scotland and sixth coldest for Northern Ireland.
The unseasonably wintry weather has caused problems in parts of the UK, including with electricity, farming and agriculture, and the road network.