People across the country are bracing themselves for a weekend of high heat, with temperatures set to reach up to 30C in the coming days.
According to Met Éireann's provisional data, the highest temperature today was recorded at Oak Park in Carlow where the mercury hit 30.4C.
The highest temperature ever recorded in Ireland was 33.3C taken in Kilkenny Castle in 1887.
A status yellow high-temperature warning has been issued for the whole country, with Met Éireann saying it will be "very warm or hot on Friday and Saturday".
The warning is in place from midday on Friday until 6am on Sunday.
The forecaster said: "Very warm or hot on Friday and Saturday with maximum temperatures generally of 27C to 29C and locally higher.
"Warm overnight with minimum temperatures generally around 15C. Temperatures may not be as high in coastal areas due to sea breezes, particularly in the northwest."
A status yellow high-temperature warning is currently in place for Munster and Leinster and will remain in place until midday on Friday.
The highest temperature at our synoptic stations today was at Oak Park, Co Carlow with 29.2°C, which is 9.3°C above its 1981-2010 long term average and the highest August temperature in Ireland since 2003📈🌡️ pic.twitter.com/F4hdFpd60G— Met Éireann (@MetEireann) August 10, 2022
A weather advisory for hot weather is currently in place for the entire country and will remain in effect until midnight on Monday.
UV levels are forecast to be “high” for much of the country on Thursday, due to widespread sunny spells with little cloud, the meteorological service said.
High demand with thousands of visitors flocking for Puck Fair and low levels in reservoirs in the vicinity has led to overnight water restrictions in the Killorglin region.
The restrictions are likely to continue until Friday. However, the Killorglin town centre where this year’s King Puck has been installed is not affected, Irish Water has confirmed.
Water was restricted in several outlying areas between Killarney and Killorglin and including nearby Milltown between 11 pm and 7 am, to allow reservoirs to replenish themselves.
Oliver Harney of Irish Water said there was “high demand” in the vicinity of Killorglin where the Puck Fair was taking place.
Thousands of visitors have arrived for the ancient annual fair and the event drew record crowds on Wednesday, coronation day.
Meanwhile, Mr Harney has urged the public to do what they can to conserve water.
“Small changes can make a big difference,” he said.
These included taking a shower rather than a bath and spending less time in the shower.
Irish Water has also warned that it is watching closely to see if further water restrictions will be needed as the hot spell continues.
Interventions are already underway at over 13 water supplies, and many more are on a watchlist due to worries that they may run dry.
A status orange forest fire risk is in place until next Tuesday. It has been issued by the Department of Agriculture due to the current weather conditions and expected level of risk over the coming days.
On Thursday afternoon, there were reports of a large fire in the Mossgrove area of Cork near Béal na Bláth.
Huge plumes of smoke were seen rising from the area as emergency services attempted to get the blaze under control.
Just flew over it there, impressive looking! pic.twitter.com/zHa45PRGSM— Diarmuid McCarthy (@DiarmMcC) August 11, 2022
Advice to prevent wildfires is to not use barbeques in woodland, and if you see a fire report it to the emergency services.
Another large blaze was spotted in Ferns, Co Wexford near the GAA grounds.
Tonight will be mild with temperatures unlikely to fall below 10C to 15C, however they will stay above 17C in some areas. There will be a light breeze but otherwise it will be a dry and clear night.
Tomorrow is to be even hotter as temperatures will be between 25C and 30C across the country, but they could rise into the low 30s in some inland parts of Munster and Leinster.
There will be no let-up in terms of the heat on Saturday, but thundery downpours will bring the temperature down to the mid-twenties on Sunday, and Monday will see a return to regular temperatures for this time of year.
Meanwhile, Ireland's electricity system is experiencing "tight margins", according to EirGrid, due to low wind, limited electricity imports, and forced outages at a number of generators.
EirGrid issued a system alert (previously known as an amber alert) warning for the potential for temporary electricity supply issues.
Joanna Donnelly, a meteorologist with Met Éireann, said it was particularly important that the vulnerable take precautions during the hot weather.
“We’re just not acclimatised to those sorts of temperatures here in Ireland.
“There are vulnerable people in society that need that extra caution overnight especially,” she said.
Ms Donnelly advised people to stay hydrated, close curtains and windows throughout the day and try to keep the temperature in the bedroom as low as possible.
“An anticyclone just moved up over the country and its warm air circulating around, just getting warmer and warmer each day because it hasn’t changed, it hasn’t moved off yet,” Ms Donnelly told Newstalk Breakfast.
“We are actually getting some warmer air moving up over the country from later on today adding to the heat that we’ve been building over the last few days.”
Heatwaves are sweeping the rest of Europe as well, as climatologist John Sweeney has warned the world was effectively reaping the rewards of inaction on climate change.
Cork City Council and the Cork Simon Community have measures in place to protect the city's homeless population from the heat.
“On receipt of the warning for high temperatures all service providers have been asked by Cork City Council to alert all clients in their facilities to the risks involved.
"Cork Simon, who run the Outreach Service, are providing sun-cream and bottled water to all service users. They will conduct extensive outreach checks and engage with anyone rough sleeping to try and encourage them to present to the Day Services and the Accommodation Placement Service," a Cork City Council spokesperson said.
"The Accommodation Placement Service Office run by Cork City Council will also be providing bottled water to any client in need of support who present to us during this time."
They are also asking the public to contact Cork Simon at 021 4278728 or email them at email@example.com if they have concerns about anyone who is sleeping rough.