Nearly three-quarters of shops have put on sales in recent days as gloomy weather compounded the misery on the high street.
Some 73% of stores advertised special offers last week, up from 40% three years ago, according to figures from PwC, while discounts were deeper than a year ago.
The figures, which underline the plight of the high street as shoppers cut back on luxuries, come as retailers face paying their quarterly rent bill.
The beleaguered sector gained a boost from the Queen's Diamond Jubilee but June's erratic weather is since thought to have hit demand, particularly for fashion items.
The average price discounts being advertised were 47%, up slightly from 45% in 2011 and 2010, the survey of 100 retailers on UK high streets added.
PwC's chief retail adviser, Christine Cross, said: "UK consumers are good at celebrating Jubilees, football prowess or potential Olympic glory but they are proving less willing to part with their cash except when the sun comes out or goods go on sale.
"Clothing purchases are weather-related and canny consumers also know mid-June means worried retailers who need to clear stock to leave room for new lines."
PwC said supermarkets were suffering "troublesome" retail trends as shoppers continued to show their "love affair with value".
However, the wet holiday weather has benefited pubs and fast food chains by encouraging people to eat out rather than have barbecues at home.
Retailers are hoping that some late summer sun and the Olympics will boost trade in the coming weeks, PWC added, but consumers will continue to be cautious as the eurozone crisis dents confidence.