Three consecutive days when the maximum daily temperature exceeds a pre-determined threshold. In Scotland, believe this is 25°C. Can be higher elsewhere in the U.K. (In London, it's 28°C).
You're right.
weather.metoffice.gov.uk
www.metoffice.gov.uk
The original heatwave thresholds were based on a reference climate period for 1981-2010. The heatwave definition was intended to be flexible and to be reviewed and revised in order to follow our changing climate and represent heatwaves relative to the “current” climate. Therefore the thresholds are moving to the most recent 1991-2020 climate averaging period introduced in January this year. 6 counties are moving from a 27°C threshold to 28°C, one from 26 to 27°C, and one from 25 to 26°C.
The central map above shows the original thresholds, the right hand one the updated thresholds and, as an additional demonstration of our changing climate, the left hand one shows what they would have been if we had had this definition in place for 1961-1990.
Counties changing from a 27C to a 28C threshold:
Surrey, Berkshire, Buckinghamshire, Bedfordshire, Hertfordshire, Cambridgeshire
Counties changing from a 26C to a 27C threshold:
Lincolnshire
Counties changing from a 25C to a 26C threshold:
East Riding of Yorkshire
Didn't Billy Connolly say 'Scotland has two seasons.... June and Winter...'
I honestly do not feel the (UK) cold. I despise UK heat though.
You should consider a decent sized ceiling fan as an alternative. When I lived in New York 30+ years ago I read an article about these: back then the argument was that you got 90% of the effect of full aiir-conditioning at less than 10% of the cost. Given the rise in electricity prices since then I suspect the balance of costs favour a ceiling fan even more.
You're right.
I found this web page on the Met Office website for anybody interested. No text to quote from the page as it's mainly a map of the UK with different temperature thresholds, with basically the south east of England being 27-28 degrees C, Midlands and south west being 26 degrees C, and everywhere else being 25 degrees C.
What is a heatwave?
Find out more about heatwaves and what to do when they occur.
Also, to answer the original question, I found this web page, which demonstrates how the heatwave thresholds have changed over the years:
UK Climate Change in action
Met Office heatwave thresholds are to be updated ahead of Summer 2022 as the UK sees impacts due to climate change.
So it does appear that the heatwave thresholds are continuously reviewed. They were last updated in 2022, so fairly recently. I could certainly see them change again in my lifetime.
I knew somebody would pick up on this. I thought putting basically in italics might suggest I'm summarising, but maybe not.
No, the last thing we need is more air conditioning. They are electricity hungry and the heat they pump out just makes the outside hotter.
In today's Health & Safety, risk-averse, society I doubt that ceiling fans would be allowed. I haven't seen one in years! Too much risk of someone jumping up and getting their head sliced. Can't say I agree, but it's the society we now find ourselves living in.
There are plenty of places selling them. The point of a large fan (I think mine are around 1.8m diameter) is that it moves a lot of air fairly slowly. My installations are definitely *not* H&S compliant because I have fairly low ceilings. The rotating mass is low and, although you'll certainly feel it if you get in its way, it has never drawn blood.
I'm looking at a website called lights.co.uk right now. Seems to have a good selection of styles.
Ah, you're one of these people that "run hot". It's an actual thing, and I have a doctor hillwalking mate who is the same as you, so he uses a flimsy little sleeping bag that weighs nothing, whereas I "run cold" and take my sea to summit 3 season bag!
Sometimes I think I'd prefer to run cooler, because I can make myself warmer with layers etc but can't make myself cooler really.Ah, you're one of these people that "run hot". It's an actual thing, and I have a doctor hillwalking mate who is the same as you, so he uses a flimsy little sleeping bag that weighs nothing, whereas I "run cold" and take my sea to summit 3 season bag!
Hope to meet you up the hills one day!
Running a bit colder than most certainly helps on days like today, as I appear marginally less dishevelled than my fellow passengers on 1F22 this afternoon! I've done a fair bit of warm weather hillwalking too, mostly in Mallorca, and it comes in handy there. But carrying 2kg more weight on multi day hikes in the winter is a lot less fun.....so as you say, swings and roundabouts! But I think I prefer the ability to put some extra layers on when I'm cold to being roasted and not having any more layers left to remove!
I think on balance I'd also prefer that option!
I'll ask my doctor friend if that's an option. I suspect probably not!I think on balance I'd also prefer that option!
Maybe if I go to a sauna/steam room every day for a year I can acclimatise?
If you could ask them for a David Lloyd gym+spa membership on prescription that would probably do the trickI'll ask my doctor friend if that's an option. I suspect probably not!
Not sure that would qualify for social prescribing.....If you could ask them for a David Lloyd gym+spa membership on prescription that would probably do the trick
As @styles said in post #4, the thresholds were revised at the start of the decade to be relative to the average temperatures of the previous three decades. They'll do it again at the start of the next decade. As it seems pretty much every year recently has been hailed as the 'hottest on record', a baseline of 2001-2030 is almost certainly going to have higher averages than the current 1991-2020. Therefore 10°C above average is going to be higher than the current values.
Nobody ever makes this argument about heating in winter though. People accept that some level of heating is required during the coldest days, but don't seem to accept that some level of cooling is required during the hottest days. It's bizarre.
The same thing applies in both directions: in winter you don’t want to let the cold in/the heat out, and in summer you don’t want to let the heat in/cold out.
You're entitled to your view, but just remember that if flats are built without air conditioning, people will add it for themselves. And these systems are far more wasteful than those built into the buildings. For example, my system uses 5 m³ of water per day - and I run it basically 24/7 during summer.
Not sure where you live, but here in Berkshire, we hit the tropical high of about 24C this afternoon. House seems perfectly pleasant this evening with just the fanlight open.
