June is on target to be the wettest since 1860.
So far this month, 150mm of rain has fallen across England and Wales when the average is 65mm.
MeteoGroup, the Press Association's weather service, said that only another 8mm more of rain is needed to beat the current record of 157mm and, with thunderstorms due later this week, it is likely to happen.
The last time there was such a deluge was when Queen Victoria was on the throne although fours years ago the total was 145mm.
The latest unwanted record comes after the dampest April across England and Wales since reliable rainfall records began in 1766.
The record breaking is no comfort to many parts of the country that have suffered floods, despite May being fairly normal in rainfall terms as it was close to the 30-year average.
MeteoGroup's forecast manager, Michael Dukes, said that the chances of just one month beating the rainfall record was about one in 250.
To add to the misery, it is also likely to be the coldest June since 1991 with an estimated Central England Temperature (CET) of just 13.3C, when the average CET for the time of year is 14.5C.
"With just a few days of June to go, MeteoGroup's data show that we are just a few millimetres short of breaking the June record," Mr Dukes said.
"Substantial thundery rain is in MeteoGroup's forecast for Thursday, in response to the temperature daring to surge into the high 20s in the South East.
"Cooler weather will follow over the weekend with showers, so it seems almost inevitable that June 2012 will enter the record books for all the wrong reasons."
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