The World Meteorological Organization (WMO) defines a heatwave as:
‘A period of marked unusual hot weather over a region persisting for at least three consecutive days during the warm period of the year based on local climatological conditions, with thermal conditions recorded above given thresholds.’
Observational (measured) data show mixed heatwave trends across the UK. There is significant regional variation in heatwave trends, with the South East of England experiencing fewer long heatwaves, but slightly more short term eatwaves. In some parts of the country, but not everywhere, there are increasing trends in the frequency and duration of heatwaves.
UK heatwave trends appear to be strongly associated with changes in natural oceanic cycles, in particular the Atlantic Multidecadal Oscillation (AMO). Ocean cycles could overwhelm effects of a warming climate in the near future. In the long term global warming should eventually lead to more frequent and more intense heatwaves ... but long term climate predictions are frequently wrong. Actually, almost always wrong !
Since the 1960s, UK summers have become about 1°C hotter on average. This positive trend followed a slight cooling during the 1940s and 50s. A recent review of weather stations operational for more than 85 years found positive trends in the number and length of heatwaves at some locations. There were also declines in the duration of long heatwaves in the South East since the 1970s, but a slight lengthening of shorter ones.
The study found that natural Atlantic Ocean cycles had a significant influence on both the frequency and length of heatwaves in the UK. Warmer UK temperatures could boost consumer spending and domestic tourism.
An influential paper suggests rising temperatures would result in annual heat-related deaths of 7,000 in the UK annually by the 2050s. This compares to fewer than 2,000 heat-related deaths per year on average in recent years.
the paper is the usual wild guess climate alarmist nonsense.
In most countries, heat-related deaths are falling even as average temperatures rise. For the UK as a whole, theres no obvious trend, but in London, a decrease has been observed over the 20th Century.
Cold-related mortality is much more significant in the UK and internationally. There are 20 times as many cold-related deaths as heat-related deaths worldwide, and the UK has had 35,000 cold-related deaths a year on average over the past 5 years. So global warming should reduce cold-related deaths far more than it could increase heat-related deaths. The so-called "studies" don't like to mention that.
