That makes it the hottest April since records for the Central England Temperature (CET) monitor began in 1865, a spokesman said.
The previous warmest was recorded in April 1865, when a mean temperature of 10.6 C was noted.
Met Office spokesman Barry Gromett added that the last 12 months has also been the hottest rolling period on record and fitted with projections that the country is continuing to get warmer.
"It's all part of a trend," he said. "We've seen these types of records not only in April but also in the last 12 months in general.
"2006 was remarkable in what it gave us in terms of the warmest year on record, the warmest month [last July] and the warmest autumn."
He added that the latest figures are "fully consistent" with projections of raising temperatures and climate change across the world.
CET is the longest continually available measurement of temperature in the world and is based on recordings in an imaginary triangle roughly enclosed by Bristol, Lancashire and London.
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