Urgent action was vital to help ready many aspects of Britain for such extremes, Environment Agency chairman Chris Smith said.
Data showed one in every five days saw flooding in 2012 but one in four days saw drought, the agency reported.
Meteorologists have expressed concerns extremes of weather may increase as global temperatures slowly rise, the BBC reported Monday.
"The extremes of weather that we saw last year highlight the urgent need to plan for a changing climate," Smith said.
"In 2012 we saw environmental damage caused by rivers with significantly reduced flows, hosepipe bans affecting millions and farmers and businesses left unable to take water from rivers.
"But we also saw the wettest year on record in England, with around 8,000 homes flooded," he said.
"More of this extreme weather will exacerbate many of the problems that we already deal with including flooding and water scarcity, so taking action today to prepare and adapt homes, businesses, agricultural practices and infrastructure is vital."