Whilst Edinburgh struggles to get an official heatwave even in this era of ongoing climate change, it turns out that I don't actually have to go all that far from here to find a location where an official heatwave has just been recorded. That location is Charterhall in the Scottish Borders and it turns out that the maximum temperature even on Tuesday was 25.52°C.
Yesterday's maximum temperature at that same station was 27.86°C and today's temperature has exceeded 28°C there. This makes today the third day in a row in which the temperature at Charterhall has exceeded 25°C which means that an official heatwave has just been recorded there as a result.
Hawick is some distance away from Charterhall but Charterhall is the nearest major weather station to Hawick. This means that if I was still down in Hawick just now, there is a good chance that I would currently be in the midst of an actual official heatwave along with our neighbours down south.
It turns out in fact that this is actually officially heatwave number 3 at Charterhall with the other heatwaves occurring 23 to 25 June 2026 and 8 to 10 July 2026 with the hottest day being on 9 July 2026 with a maximum temperature of 29.30°C.
From the same website (extremeweatherwatch.com ) as where I get all of the date records for the botanic gardens in Edinburgh though, I have also find some useful information which will help us to understand why it's so difficult for us to get an official heatwave here in Edinburgh.
On that site, there is a section called streak finder and in that section, I was able to set that up to show the number of consecutive days with temperatures reaching or exceeding 25°C which is the heatwave threshold for here as well for most of the rest of the UK away from SE England. All I then had to do is to look at only those entries on that list with 3 or more days exceeding that threshold as that is what actually defines an official heatwave.
These records go all the way back to 1959 but even with that, these records show that there has only ever been 5 official heatwaves albeit with all but one of those heatwaves occurring within this current century. According to those records, the last such heatwave occurred on 8 to 10 August 2022. That was a year in which there was actually two official heatwaves (the other one occurred on 16 to 18 July 2022) but there has been no official heatwaves here in Edinburgh since then, at least not at the botanic gardens.
Originally Posted by: johncs2016