Right here on the Met Workplace, we have now been recording temperatures way back to 1910 and have recorded standardised every day temperatures for the reason that Sixties. Nevertheless, there are a selection of components to confirm temperatures and any related information which guarantee a good comparability and consistency throughout our annals.
How are temperatures measured?
Because the Sixties, temperatures quoted by the Met Workplace have needed to come from stations that meet particular standards and are usually maintained and inspected by our specialist groups. Solely knowledge that’s measured to the closest decimal level are included, that means that observations from sure stations that measure to complete numbers, equivalent to METAR stations at airports, can’t be utilized in these standardised outcomes.
Inside these stations, thermometers must be housed in a white slatted field with its door dealing with north, referred to as a Stevenson display, which retains the thermometer away from direct daylight however air circulation fixed.
Consistency within the areas of those bins can be essential, mounted 1.25m excessive over degree, grassy floor. Man-made supplies equivalent to concrete can have a big impression on outcomes by properties equivalent to warmth retention, and because of this the Stevenson screens needs to be positioned not less than 20m away from concrete or onerous standing, and solely half of the realm inside a 100m radius needs to be fashioned of artificial surfaces.
When are most temperatures formally recognised as a brand new file?
There’s a verification course of to the every day actual time knowledge which has to undergo high quality management previous to it’s launch, equivalent to cross referencing with close by stations for any inconsistencies. Nevertheless, for information to grow to be official extra rigorous high quality management is carried out over an extended time period, doubtlessly a number of months, earlier than they are often recognised as a brand new file. These embody wider cross checking between stations and websites, understanding of the climate on the day and what was anticipated in comparison with our forecasts.
Extra to those validations, bodily inspections by a crew of engineers imply they’ll examine that gear is working because it ought to with no anomalies, including a further layer of verification to make sure reported information are right.
What are we studying from the previous?
There have been important impacts from excessive temperatures over the previous century, with many classes learnt to minimise these results. In 1911 when temperatures reached 36.7°C, round 4,000 folks died in London alone in the course of the heatwave interval. Droughts impacted water provides, lack of grazing for cattle elevated milk costs, and sure outside employers needed to modify the working hours of their workers with a view to keep away from the warmth.
The development for these excessive temperatures has additionally been rising, with 9 of the ten hottest days on file within the UK falling from 1990, three of those since 2019. Nevertheless, know-how has developed, and while these temperatures nonetheless pose a big danger to life, the power to forecast extra practically every week forward permits folks to organize and adapt their actions to attempt to minimise the consequences that warmth can carry.
