The long hot summer of 1976 which eventually ended in September
of that year, was the culmination of a 16-month dry spell - the
longest recorded over England and Wales since 1727.
Why did it happen?
The summer of 1976 had its origins in the weather of the previous
year. The dry, warm weather that set in during May 1975 over much
of England and Wales was followed by dominant warm, dry, sunny weather
throughout that summer and led to the development of large soil moisture
deficits by the end of August.
Summer deficits usually disappear with winter rainfall, but the
autumn and winter of 1975 were drier than usual and soil moisture
deficits were slower to disappear. Even by mid-February 1976 there
were still small areas where the deficits had not been made up
and, as a result of a dry March and April, deficits started to
increase again so that by the end of April they were already larger
than usual for the time of year. During the summer, deficits even
larger than in the previous year built up.
Rainfall down by half
Without significant rain it was a very dry scenario and, in the
event, only 50 per cent of normal rainfall between June and August
fell. There was no rain at all over much of England and Wales
for several weeks in the latter part of July and for most of August.
In particular it was dry in many parts of south Wales, south-west
and southern England for 35-42 days until rain was recorded on
27, 28 or 29 August.
Temperatures were highest in the southern and south-eastern areas
of the country - amounting to a whopping 4 °C above average
between June and August from Devon across to Cambridgeshire. Heathrow
had 16 consecutive days with temperatures over 30 °C from
23 June to 8 July, its longest spell on record.
A hotter spot between 23 June and 7 July
During this spell of hot weather temperatures exceeded 32 °C
at one or more stations in the UK every day, and Cheltenham had
11 such days including seven in succession from 1 July - recording
35.9 °C on the 3rd.
Starting over East Anglia the heatwave intensified, peaking over
eastern England on 26 June, then extending to Wales, south-west
and northern England and north to cover the Scottish mainland
by 1 July.
Skies were almost cloudless over much of central and eastern
England, parts of East Anglia, Kent and East Sussex having an
average of more than 14 hours of bright sunshine each day over
the period. On 30 June exceptionally dry air also covered much
of East Anglia and southern England.
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