The Met Office said the area of high pressure, which has brought fine conditions across the UK over the last few days, is forecast to continue through the weekend and into next week.
The highest temperature of 2023 was recorded in Cardiff on Monday at a balmy 23.4C.
Forecaster Simon Partridge said it could get even warmer over the weekend with highs of 24C possible in south-east Wales and around the Bristol Channel on Saturday and Sunday.
Other areas around the UK can look forward to temperatures reaching high teens and early 20s.
“We’re slowly getting there. Hints of summer,” Mr Partridge said, adding: “For a bank holiday weekend it’s pretty rare to be that dry and sunny I guess, so we’re not doing too bad.”
Rain is unlikely to trouble the UK over the next few days, with Met Office deputy chief forecaster Steven Keates saying indications are that the dry, bright weather is likely to continue for most – with little in the way of rain throughout next week.
Met Office chief forecaster Paul Gundersen said: “The jet stream sitting to the north of the UK is holding unsettled weather systems at bay and allowing high pressure to dominate bringing fine weather to the vast majority of the UK.
“The current position of the high-pressure means we will see a westerly air flow over the UK, a cooler direction than if air was being brought up from the south, and areas such as Spain or Africa.
“Therefore, we are not likely to reach heatwave conditions, but temperatures will still be warm reaching the low 20s for many, particularly in the South West and southern Wales.”
Meanwhile, travel experts are warning of a busy time on the roads.
RAC spokesman Rod Dennis said: “We fully expect families to make the most of the largely fine weather over the coming days which is we’re forecasting the busiest late May bank holiday since before the pandemic.
“Into next week and half term for many parts of the UK, day trips will also be a big feature with popular routes to the coasts and countryside becoming busy.
“Getting away early in the morning or delaying trips until the evening are the best way to avoid the inevitable delays.
“No-one wants a breakdown to get in the way of them and time with family and friends, yet so many of the jobs our patrols will go out to are completely avoidable if drivers complete a few checks before they get out onto the open road.
“Ensuring oil and coolant levels are where they should be is a must, as is checking tyres are free of damage and are properly inflated.”