The average price tag on a home coming freshly onto the market jumped by over £2,800 in May - meaning house hunters in some areas now face record high amounts being demanded by sellers.
Across Britain, the average asking price is £308,290 - £2,841 or 0.9% higher than in April, according to the figures from Rightmove.
The website, whose records go back over a decade, said Wales, the Midlands and the North West of England are "bucking any Brexit blues" - with average asking prices in these areas having reached new all-time highs.
It says average asking prices in Wales have broken through the £200,000 barrier for the first time.
In Wales, the average asking price is £200,386.