Temperatures in Maidenhead reached 30C today, which was described by local meteorologist Roger Brugge as 'remarkably high' for a mid-September day.
Since he began his records nearly 30 years ago, he has only recorded two temperatures this high in September twice - 30.4C in 2013 and 30.5C in 2006.
He said the increase in temperature was due to northward movement of very warm air in southern England from south-west Europe.
Roger, who works at the meteorology department at the University of Reading, said: "Looking further back in time, no similarly high temperatures were recorded by the weather station at Hurley which operated between 1953 and 1992, and university records from Reading suggest that we need to go back to 1926 for a similarly high reading in the area this late in September."
Temperatures are expected to remain warm but slightly cooler for the rest of the week.
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