Tuesday, September 19, 2017

August 2017 is the second hottest August on record - the #climate is changing

Sou | 8:21 PM Go to the first of 23 comments. Add a comment
Summary: August 2017 was the second hottest August on record. The 12 months to August 2017 was the second hottest September to August period on record.

According to GISS NASA, the average global surface temperature anomaly for August was 0.85 °C, which is 0.14 °C less than the August 2016. August 2017 was 0.05 °C hotter than the next hottest August in 2014, which had an anomaly of 0.80 °C.

Below is a chart of the average of 12 months to August each year. The 12 months to August 2017 averaged 0.91 °C above the 1951-1980 mean, which was 0.13 °C cooler than the 12 months to August 2016.

This makes it the second hottest September to August 12 month period on record.

Figure 1 | Global mean surface temperature anomaly for the 12 months to August each year. The base period is 1951-1980. Data source: GISS NASA

Next is a chart of the month of August only. This August was 0.85 °C above the 1951-1980 average and was the second hottest August on record. It was 0.14 °C cooler than August 2016, which was 0.99 °C above the 51-80 mean. Hover over the chart to see the anomaly in any August:
Figure 2 | Global mean surface temperature anomaly for the the month of August only. The base period is 1951-1980. Data source: GISS NASA

NASA GISS Seasonal Cycles

NASA GISS has recently started showing this chart, which is another way of looking at global temperatures. It is a plot of monthly temperatures over the year since 1880. The black dots show the months for 2017.

Figure 3 | GISTEMP Seasonal Cycle since 1880. The base period is 1951-1980. Data source: GISS NASA

ENSO year comparisons

In the chart below you can see the global mean temperature trend by month. It shows the strongest El Niño years since 1950, which were followed by a La Nina. I've included the 2015-17 period for comparison. The BoM ENSO update is now showing inactive, with no ENSO event likely this year.

Of the seven very strong, strong and strong to moderate El Ninos since 1950, there were only three that were followed by a La Nina (not including 2015-17, when there was no La Nina).

The chart below spans a three year period. That is, for the 2015-16 El Niño and subsequent, it goes from January 2015 to December 2017, or would if the data allowed. (For a more detailed explanation see the HW articles: El Niño to La Niña years with more detail here.)

Figure 4 | Global mean surface temperature for strong or moderate/strong El Nino years that were followed by a La Nina. Also includes the 2015/16 El Nino for comparison. Data source: GISS NASA

Where was it hot?

In July it was very hot in much of Antarctica, for Antarctica that is (which is a very cold place). In August some parts of Antarctica were much hotter than would be expected, while other parts were cooler. Move the arrow at the left to the right to compare August with July.

June 17
May 17

Figure 5 | Maps showing mean surface temperature, anomalies for August and July, from the 1951-1980 mean. Data source: GISS NASA

Year to date chart

For the record, here is the year to date progressive chart. You need to understand what it is to make sense of it. The chart below shows the average temperature for the year at each point on each separate line on the chart. The topmost line is last year (2016). At January, the point is just the anomaly for January. At February, the point is the average anomaly for January and February. At August, it's the average of January to August inclusive - all the way to December, which is the average for the whole year.

So the 2017 year shows that the average for the period January to August is 0.93 °C. This is 0.13 °C lower than the average for the year was this time last year at the end of the massive El Nino. The average over the entire 2016 year is 1 °C (the point marked for December on the 2016 line) so although it's not completely impossible for this year to be another hottest year, the next few months would have to be very hot for that to happen.

Figure 6 | Progressive year to date global mean surface temperature anomaly. The base period is 1951-1980. Data source: GISS NASA

The anomalies for the rest of the year would have to average more than 1.12 °C for 2017 to be hotter overall than last year. That seems highly unlikely. If the anomalies have an average of 0.75 °C or more then 2017 will end up hotter than 2015. In that case 2017 will be the second hottest year on record. That's not impossible.


  1. Also, July's average was adjusted up by 1/100th of degree, keeping it as the hottest July in the GISTemp data, and actually doubling its lead over 2016.

  2. This blog's claim should be "The world's least viewed site on global warming and climate change."

    WUWT must be quaking in their boots.

    1. Anonymous

      Isn't that what you said the last time you visited?

    2. No. I said, "The world's second least viewed site on global warming and climate change."

      This is an update, biscuit boy.

    3. Anonymous

      Whatever. The point is you are identifiable, even though you are Anonymous, by the tedious, unimaginative and boring point you make.

      If you have nothing interesting, original or interesting to say then refrain.

    4. I think what Anonymous is getting at is the logical conclusion that, because more people read the tabloids than read the scientific literature, August was *not* the 2nd warmest on record and the earth may be hollow. Furthermore, candy bars are nutritionally superior because more people consume them than consume oatmeal.

      That aside, we all know there's only thing capable of making WUWT shake in its boots: the thought of Mr. Watts actually making good on his promises to confront the real scientists at the real conferences (if only his followers will provide some $$) and crush them face-to-face with devastating critiques and honest working-man wisdom.

    5. This comment has been removed by the author.

  3. Is it kind? Is it true? Is it necessary? I suspect Hotwhopper is busy elsewhere. We are all grieving the wonderful Andy Skuce, and you would do well to look at his story, someone of great value who made a journey from ignorance to knowledge with all honesty, curiosity, and integrity. In providing you with this link, I am treating you as a real human being with genuine interest in positive as well as negative things, returning good for intended (and ineffective) harm.

    "Changing Climates, Changing Minds: The Personal" by Andy Skuce

    "Nobody comes into this world with a fully-formed opinion on anthropogenic climate change. As we learn about it, we change our minds. Sometimes, changing your mind can be easy and quick; sometimes it’s hard and slow. This is an anecdotal and subjective account of the author’s changes of mind."

    It is a complete waste of time and deeply degrading to attack your host. Why bother?

    1. Thanks, Susan. There are a few things happening here in real life. For a little while yet I cannot see articles will be coming as often as they used to.

      It's not a pause or hiatus, it's more of a slowdown. The rate will rise again in the future.

    2. Thanks Sou. I too have been busy elsewhere (in "real life"), but will be back from time to time. I thought this as good a place as any to put a copy of my mini-tribute to Andy Skuce.

      My nullschool shows northern Australia is pretty hot. Hope that's not as bad an omen as I think it might be:

  4. Among the victims of heatstroke is Jo Nova, who has just made a febrile call for Australia to build 1,200 more coal fired power stations:


    1. What I find appalling is the IPA has such a low opinion of people that they try to deceive them with such rubbish. And The Australian appears to have gone insane.

    2. It works. So the coal shill govt got its second term and is carrying on its business as usual (getting rich personally while wielding the power of govt, it is no other than that). Now that is appalling. But to me most appalling is the systematic underestimation of this by my very friends and compatriots.

  5. There seems to be a lot of "Sorry, the file that you've requested has been deleted" from G00gle Drive...

    1. Thanks BJ. I will fix it when I can. Am caught up with other things at present.

  6. In case anyone missed the most extraordinary coming-out as a climate science denialist ever:


    1. Well, a more rational speech to the merry folk at the GWPF would have met with a frosty reception. I do wonder what purpose such a speech serves other than to affirm one's adherence to the fossil fuel industry's cause.

      Lawson and Ridley of the GWPF were involved in the Leave campaign for the Brexit referendum. The accuracy of statements made by the Leave campaign can, at this stage of the game, be readily compared with the reality of the Brexit negotiations. And the level of accuracy seems to have been well up to the usual standards of the GWPF.

    2. Since they won, they don't have to be very cryptic anymore. I see nothing extraordinary here.

  7. Adélie penguins are suffering from the impact of human caused climate change:



    Some media are not including any explicit mention of climate change in the phenomenon, including Newscorpse:


    and the newly "balanced" ABC, which fears the wrath of its conservative federal government who would rather that the ABC report in a Murdoch style...


  8. Remaining resolutely off topic: news about the Trump administration, while appalling in so many ways, has allowed me to understand a little better the working of Anthony, Eric et al. When you are arguing with these people, imagine you are arguing with Donald Trump. No wonder these people support Trump: their mindsets, their respect for truth, is identical.

    1. 'Toxic Sludge is Good For You'. Read it then you see what you're up against. You'll also remain one of the very few for decades to come. The way my friends and allies in the climate wars stubbornly resist to see they are in a battle against criminal corporative behaviour and criminal lobbies has in fact ended my motivation to fight the fight any longer. And I wouldn't to fly around in a gutted car like some journalists these days.

    2. My favourite of the moment is "insect nerve agents don't harm insects", courtesy of neonicotinoid manufacturers.

    3. Can't say why I feel thankful for this response, but I do... This glimmer of hope, might be a complete hallucination, of perhaps a companion in the desert..


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