A temperature of 27C has been recorded at Mount Dillon in Co Roscommon, making it, provisionally, the hottest day of the year.
Met Éireann said that, pending verificiation, it beats the 25.9C reached in Athenry, Co Galway on 30 April.
The record could be broken again tomorrow when temperatures of up to 29C are forecast in long spells of sunshine.
Met Éireann said that tomorrow will be "very warm or hot" with "highest values over the northern half of the country".
However, showers are also possible in humid conditions and they may be heavy at times.
Provisional highest temperature of the year so far, recorded at #MountDillon, Co Roscommon 📍 this afternoon.
— Met Éireann (@MetEireann) June 19, 2025
Beats the previous high of 25.9 °C at Athenry on April 30th. 🌡️#BeSummerReady #SunSmart pic.twitter.com/YWbofzeoj1
The warm weather is expected to continue on Saturday, with sunny spells and showers, but temperatures will be lower, with a high of 25C.
It will be fresher and breezier on Sunday and Met Éireann said that similar conditions will likely prevail early next week.
#Pollen Forecast🌱🌳🤧📈
— Met Éireann (@MetEireann) June 19, 2025
➡️ High levels expected for today & the coming days.
➡️Grass, nettle & weed pollen in particularly high levels expected.
➡️Medium to high concentrations expected for grass, nettle & weed pollen.
Stay protected. For moreℹ️ https://t.co/ZbaJ2zLRhg pic.twitter.com/cdVEewlgRo
It comes as the UK record for the warmest day of 2025 was broken twice today
A temperature of 32.2C was measured in Kew, west London, hours after 30.8C was reached in Wisley, Surrey.
Much of Britain is expected to be under "heatwave conditions" over the weekend.
The UK Health Security Agency (UKHSA) has issued an amber heat-health alert for England that will remain in force until 9am on Monday.
The agency warned that "significant impacts are likely" across health and social care services because of high temperatures, including a rise in deaths, particularly among those aged 65 and over or people with health conditions.
Heatwave conditions in the UK are met when a location records a period of at least three consecutive days with temperature values meeting or exceeding the threshold for that location.
Across much of the north and west of Britain, this threshold is 25C, but in greater London and the south-east, it is higher, at 28C.
HSE urges people to use sun protection
The HSE's National Cancer Control Programme (NCCP) and Healthy Ireland are advising people to use sun protection.
Skin cancer is the most common form of the disease in Ireland with over, 11,000 cases annually, and 1,200 melanoma cases - the most serious form of skin cancer - diagnosed each year.
It comes as the NCCP and Healthy Ireland launched the annual 'SunSmart’ campaign.
They advise people to use suncream with SPF 30+ for adults and 50+ for children, wear hats, sunglasses and clothing that covers the skin, and to avoid direct sunlight.
"The more time you spend unprotected in the sun, the more UV damage your skin is exposed to which increases your risk of skin cancer, including the deadliest form - melanoma," Dr Breeda Neville of the NCCP said.
Additional reporting PA
