Bright and sunny weather is the forecast for most of the rest of the week, with temperatures set to hover around 15C from Tuesday.
Spring weather arrived at the weekend as Castlederg in Co Tyrone recorded a temperature of 15.3C.
But the temperature is set to match and surpass that by the middle of the week, according to the Met Office.
The mercury hit just over 20C in Scotland on Saturday, the highest temperature recorded in the UK since last October.
Temperatures for the rest of the week from Tuesday will be in the 14 -16C range, though early mornings will remain cool at around 6C. Western counties will see some cloud at times but the east will see some lengthy clear periods, where there will be some frost in the mornings.
All parts will have a dry day on Monday with variable amounts of cloud and some bright or sunny spells, the Met Office said. It will be mild across the west, but onshore breezes will keep the east coast colder.
Maximum temperature will be 12C.
It will be dry and sunny from Tuesday to Thursday with light winds and very mild as the days progress. Expect some overnight mist and fog patches, the Met Office said.
The highest temperature in the UK on Saturday was 20C in Kinlochewe, north-west Scotland, which surpassed Friday’s high of 17.5C recorded in Wiggonholt, West Sussex.
The average temperature across Northern Ireland on Saturday was 14C — well above the March average of 10C.
This prompted many people to head for the coasts to enjoy the first truly warm and bright spell of the year.
According to the Met Office, the temperature will be around 15C for most of the week, hitting a high of 16C on Thursday.
The welcome change in the weather contrasts with the storms and icy early mornings over the last month.
Just last week parts of counties Down and Antrim were battered by strong winds, while temperatures dropped to as low 1C.