Met Éireann has said temperatures this week will be higher than normal for this time of the year.
Temperatures today are forecast to reach highs of 17C and will remain higher than average for the next couple of days.
Tuesday and Wednesday will see predicted highs of 16C.
Conditions will return to normal on Thursday, with cloud cover and patchy drizzle to accompany temperatures forecast to reach 14C at most.
Dry and spring-like today with spells of hazy sunshine breaking through after a misty start. Very mild, with highs of 12 to 17 degrees Celsius, possibly a little higher locally. It will be mildest in sunshine, and away from southern and eastern coasts, where mist/fog may linger pic.twitter.com/J1ibK6iB2B— Met Éireann (@MetEireann) February 25, 2019
The unseasonably warm weather is caused by a high pressure area over continental Europe which is feeding up warm air from the Iberian peninsula.
It has led to the UK Met Office recording an all-time high for February, with the mercury reaching 20.3C at Trawsgoed, Ceredigion in Wales.
It's reached 20.3 °C at Trawsgoed, Ceredigion making it the UK's warmest February day on record. It's also the first time we've recorded over 20 degrees in winter pic.twitter.com/naGaJbjjWS— Met Office (@metoffice) February 25, 2019
The previous record had been 19.7C, which was set in London on 13 February 1998.
It is also the first time a temperature higher than 20C has been recorded in the UK in winter, the Met Office has said.