Met Éireann has forecast prolonged warm and sunny weather for the week ahead.
It said that temperatures will reach the mid to low 20s in some places, with the warmest conditions away from the east coast.
A temperatures of 22 degrees was recorded this afternoon at Mount Dillon in Co Roscommon.
The forecaster said it will mostly dry this evening with spells of hazy sunshine.
Tomorrow will also be warm, dry and largely sunny and temperatures could reach up to 24C in parts.
Wednesday and Thursday will have temperatures of between 18C and 24C degrees.
Over the bank holiday temperatures are set to reach the high teens or low 20s in the east and possibly reach the mid-20s in some places in the west.
Met Éireann also said the grass pollen risk could rise to moderate during warm weather, which will trigger symptoms for some hay fever sufferers.
It said the week ahead does not meet the definition of a heatwave, which is described as temperatures in excess of 25C for a period of five days in succession.
Saturday was the hottest day of the year with temperatures reaching 23.3C at Mount Dillon.
Ahead of the summer holidays, the Royal National Lifeboat Institution (RNLI) is urging children to be safe when near both coastal and inland water.
It said the public should remember four safety messages: "Stop and Think, Stay together, Float, Call 999.
"Think: Is it safe to be here? What are the potential dangers? Stay together. Be aware of each other and never become isolated.
"Float. If you fall into water, you are likely to get cold water shock. This can make it temporarily difficult to breath and induce panic. If you float for 60 seconds this will pass and your breathing will get back to normal.
"Don't hesitate to call for help. Call 999 or 112".