Met Éireann has issued an advisory for hot weather this week with temperatures in many places of up to 30 degrees..
The advisory from Wednesday is for hot weather developing and continuing through the rest of the week and into the weekend.
It warned about the possibility of heat stroke for elderly people and that UV levels will be high in the sunshine. It will also be “uncomfortably warm” at night.
Temperatures will not fall below 18 or 19 degrees in parts of the southeast at night, Met Éireann forecaster Brandon Creagh said on Sunday.
Weather advisories are usually followed by warnings which may be issued later in the week.
The latest forecast shows high temperatures everywhere from Wednesday, but it will be warmest in the midlands with the possibility of 29 or 30 degrees on Friday.
The forecasted weather would appear to meet the definition of a heatwave which is five days in a row with temperatures of more than 25 degrees.
This is likely to be the first time since 2003 there will be a heatwave in Ireland in August. The last time 30 degrees was experienced in the month was during the heatwave that lasted from August 4th to 8th that year.
Though that mark is still a possibility, Mr Creagh said it is more likely temperatures will top out in the high twenties.
The hot air is the result of warm air from the Continent crossing the country.
The current models are strengthening that there will be a heatwave from Wednesday and it will cover much of the country for the following days.
Mr Creagh said the highest temperatures are at the “upper end” of the ensemble weather predictions, but there is little doubt there will be hot weather from the middle of the coming week.
“The current high pressure pattern that is sitting over us is going to persist for a while,” he said.
“At the moment, it is from a northwesterly air flow, but it will change to a south-easterly air flow which will bring continental air over the country. That’s why the models are going for those really high, dry temperatures.
“If it plays out as is predicted at the moment, the hot weather will be widespread. Most areas will get into the high 20s even reaching the 30s particularly in from coastal areas.
“By Wednesday we are getting into the mid-20s and then from Thursday we will get the high-20s and the possibility of 30 degrees next weekend.”
The latest models suggest that the hot weather will remain until Tuesday of next week, but after that there is uncertainty.