Scorchio September

I take a quick look at the Central England Temperature Record (HadCET) to see how September is faring in the new era of global boiling

Back on 4th September I wrote a short piece on daily mean temperatures attained within the Central England Temperature Record (HadCET) during August 2023. At an overall mean of 16.37°C August managed to scrape a lowly and somewhat embarrassing 71st place in the grand list of 252 Augusts since 1772, with gold going to 1995 (19.14°C), silver going to 1997 (18.95°C) and bronze going to 2022 (18.71°C). I had wondered why the MSM had not blown the alarmist trumpet these last few weeks and there is likely the answer in stark digital form.

August running pretty darn cool, surely not?! Alarmists will have to purge this unfortunate fact from their minds, and I wouldn’t be surprised if somebody somewhere is being paid a lot of fudge money to save August 2023 one way or another. Hence the sudden flip to sea surface temperatures and sea ice, I guess, for how will the MSM manage to survive without their daily catastrophic headline?

New Kid On The Block

Well, one way is to invent a new form of denier. They’ve put aside climate change denial and have replaced this with heat denial. I kid you not – check this cheeky Guardian article out. I'm not really an influencer as such but, according to The Guardian, it sure looks like I am in heat denial for analysing official historic temperature data and discovering things weren’t as hot as claimed. In response I am going to suggest that so-called 'news' outlets like The Guardian are in truth denial. Perhaps they should re-brand their paper The Porky.

This brings us on to this month, and what a splendid month it has been for fine weather! One of those decent ends to the summer that crusty Boomers like myself can’t get enough of whilst Millennials/Gen-Y/Zoomers/Gen-Z stress to the max over the prophesied greenhouse apocalypse. Admittedly, there haven’t been many gloriously warm UK Septembers over the last few decades and so I wondered if this month may have broken a record or two. I thus removed the purple tunic of the heat denier, donned the orange vest of the soup throwers and went in search of the Central England Temperature record, which may be found here.

All Books & Cleverness

When it comes to considering heatwaves expertistas do something really clever – they prefer to consider mean (average) daily temperature instead of absolute maximum daily temperature or mean maximum daily temperature, the latter being an average across a sample of stations. It transpires that absolute maxima time series tend not to exhibit warming, with some series even indicating global cooling. Whoops. In turn, this it’s-as-hot-as-it-will-ever-get phenomenon tends to compress the mean maximum such that warming rates are not always as juicy as those offered by the daily mean. In short, expertistas are relying on nighttime minima to bump up the figures they prefer to use. It’s heat, Jim, but not as we know it!

Orange Vest

But today I am in my orange vest, which means I shall be looking at the mean daily temperature first and foremost for I am no longer in heat denial. Being an honest sort I’ve taken Friday 1st September as the start date for a September study and have chosen Sunday 10th as the end date for this was the last day of really warm weather. If you aggregate the Central England daily mean temperature for the period 1st – 10th for all Septembers over the period 1772 to 2023 you end up with this splendid plot:

We can see that 1st – 10th September 2023 has broken all records with a mean of 20.42°C, with silver going to 1898 (18.36°C) and bronze going to 1865 (17.99°C) – scorchio indeed! You may start throwing soup now. This year is a right royal outlier, make no mistake, which may explain the quantity of salad I’m eating.

Since I have my orange vest on I shall also report that a linear regression (black line) yielded a statistically significant warming trend of +0.43°C per century with a 95% confidence interval of  +0.16°C to +0.69°C per century (p=0.002). Don’t wait up.

Despite September 2023’s outstanding performance that’s not a lot of warming overall and we have a choice as to whether we pin this on atmospheric CO2 alone or a sizeable number of other factors that we’re not allowed to discuss. The Energy Bill that is going through UK parliament right now assumes the former, and in a short space of time us Brits will get to experience firsthand the dire ramifications of politicised science.

Wobbly Wiggly

One thing that catches my eye is that, despite a modest positive trend, a Wald-Wolfowitz runs test indicates that the series is effectively a random walk (p=0.511), so we ought to be careful how much we read into this wobbly result for the signal is slight and not considered sufficiently dissimilar from a series of random values.

The green wiggly snake reveals the world is more complex than more CO2 = more heat even if that world is only the fair nation of England. In terms of the mean daily early September temperature record we seem to be in a recent warming period, with evidence of historic warming and cooling periods that cannot possibly be mediated through CO2. Let it be said that atmospheric CO2 hasn’t suddenly exploded to fry folk this month in some glorious positive feedback loop, thus we need to look to jet stream stability and the drivers behind that. Strangely enough, the unstable jet stream idea was forwarded as the driver for global cooling back in the ‘60s and ‘70s but here it is again serving a new paymaster.

Hot Fries To Go

So that’s the bit about average daily temperature but what about maximum daily temperature? This crops up in scary headlines telling us that it was a zillion degrees in Scunthorpe Botanical Gardens or wherever, followed by some such phrase as “hottest day since records began”, this implying that Scunthorpe Botanical Garden (SBG) staff were reliably collecting daily maximum temperature data back in 1920, 1880 or even 1850 when SBG might have only started on data collection last year. Be sure to check that trick!

Statisticians, being mean and surly sorts, will remind you that hopping from station to station to maximise time-dependent data is tantamount to fraud. For example, if the hypothetical SBG recorded a record-breaking 39.8°C on 9th September 2023 but only opened in January 2011, then we have no idea whether an even hotter temperature would have been recorded there in the scorching summers of 1995, 1983, 1976, 1947, 1933 and 1911. Thus, if we are selective with our hopping we can conjure a fake warming trend.

To insure against such bias we have to fix the station sample such that the same stations have been consistently providing data over the same time period. This is why I ‘heart’ the Central England Temperature Record for it seeks to homogenise data collection over a select number of stations. This series may not capture the hottest of hot daily temperatures or the coldest of cold daily temperatures but that’s not the point when it comes to trend analysis that purports to be serious; that is, if we want to know whether hot days are getting hotter or more numerous then we have to use the same station sample over a span of many decades. To do anything else is mighty scandalous for the bods behind such high jinks will know full well what they are doing.

Hot Day Count

With ranting done what I’ll do now is count the number of days within the Central England Temperature Record that met or exceeded a daily maximum of 25°C or 30°C. I can then aggregate these counts for the period 1st – 10th for all Septembers over the period 1878 to 2023. Herewith a plot of the results:

In terms of those Olympic medals for hot days I can report that gold goes to 2023 with a total of 7 days at or exceeding a mean maximum of 25°C, with silver going to 1898 with a total of 5 days, and bronze going to 1911 with a total of 4 days. I presume alarmists will ignore those decent counts of distant hot days and focus solely on the record-breaking current year. This is mighty peculiar behaviour for in the world of statistics we suspiciously view outlying data points with… er… suspicion rather than build global policies around them.

What is interesting is that, in terms of Olympic medals for super scorchio hot days reaching or exceeding a mean maximum of 30°C, then only one year may be awarded a medal and that is 1906 with 2 days of royal roasting of the nation. This didn’t stop them burning coal or inventing the aeroplane.

The Mean Maximum

At this point some keen folk might like a slide of the mean maximum early September temperature and here it is:

September 2023  romps home again with the gold at 26.54°C, with silver going to 1911 (23.74°C) and bronze going to 1898 (23.69°C).

At this point we have a choice of gluing ourselves to the road and screaming that the world is about to end because of one outlying data point or we can ask why high temperatures were experienced right at the very beginning of the industrial era when atmospheric CO2 was down at 280ppm or thereabouts. My guess is something cyclical is happening, and in this respect it is worth looking at that wavy green snake once again.

Since I still have my orange vest on I shall also report that a linear regression (black line) yielded a statistically significant warming trend of +1.17°C per century with a 95% confidence interval of  +0.35°C to +1.99°C per century (p=0.005). What is causing this warming is open for debate (at least it should be unless we’re now all good little communists obeying the Nation State diktat).

So there we have it. We are talking about a record-breaking start to September as regards the Central England Temperature Record. My guess is that folk are going to hang on this and ignore the pretty dismal month of August (see this article) which, to my mind, isn’t that logical unless you’re into cherry picking to support your faith/economic policy/religion/ego/career/grant application/agenda (delete as necessary).

Kettle On!