David Bidstrup: When did we have the driest spring in Adelaide?

This post looks at historical data for Adelaide rainfall for the period 1839 to 2018. The data comes from the BoM website and is subject to the usual caveats – there are some records missing and the presumption is made that the records are factual and not “homogenised” to fit a story.

My interest was sparked by a report some time ago that we had “the driest spring since …” so in order to put that in perspective the following analysis was done.

Leap days were removed because my rudimentary method depends on a definite number of records between 2 dates and if leap days were included then by the time the iteration had been done 130 times the dates would be wrong. There are 45 leap days in the data record of 66,082 days and they have a total of 19.6 mm of rain total so the effect is small.

Because I wanted to look at seasonal variations I decided to do it in a way where summer started on 1 December so each “year” starts in December and runs to end November the next year. In the tables you will see years labelled 1978/79 which means the “year” starts on 1 December 1978 and runs to 30 November 1979.

Rainfall totals were found for each season and tabulated along with an annual total rainfall. By some sorting the spring totals could be ranked from “driest” to “wettest”.

The table below shows spring ranked from driest at the top, 1895/96 at 33.9 mm, to the spring of 2018/09, i.e. September, October and November of 2019, at 82.2 mm. Note that this is number 30 in a list of 180 years. Adelaide’s driest spring was 124 years ago.

Interestingly, the total annual rainfall for both years was around the same.

Annual rainfall varies from 244 mm in 1958/59 to 820.6 mm in 1850/51.

YEAR SUMMER AUTUMN WINTER SPRING ANNUAL
1895/96 64.8 124.1 143.7 33.9 366.5
1966/67 121 39.6 117.5 37.1 315.2
2007/08 49.6 124.8 187.4 37.8 399.6
1960/61 16 162 155.8 43.3 377.1
1981/82 53.8 160.2 112.4 44.6 371
1937/38 134 176 176.7 47.3 534
2005/06 94.4 121.4 59.8 51.6 327.2
1887/88 58.9 58.5 237.6 56.7 411.7
2011/12 60.8 152.6 260.6 59.4 533.4
1964/65 22.9 110.9 134.6 60.5 328.9
1899/1900 33.6 226.4 237.3 60.7 558
2013/14 124.6 134 224.6 60.8 544
1986/87 86.8 178.6 246.6 61.4 573.4
1896/97 93.1 99.1 172.8 65 430
1864/65 13 108.9 203.7 67.1 392.7
1894/95 66.4 172 249.5 69.8 557.7
2014/15 48.6 132.2 129.6 71 381.4
1884/85 53.7 88.1 205.4 71.1 418.3
1913/14 98.7 107.1 61.5 71.5 338.8
1863/64 81.1 98.5 271.7 72.1 523.4
1926/27 65.3 84.9 205.2 72.5 427.9
1842/43 55.8 109 192.1 74.2 431.1
1853/54 24.2 137.1 159.2 75.1 395.6
1968/69 151.3 135.3 172.1 75.1 533.8
1858/59 82.1 137.1 111.9 78 409.1
1994/95 59.4 127.2 229.4 78 494
1958/59 35 36.2 94.1 78.8 244.1
2006/07 57 152 156.4 78.8 444.2
1971/72 115.2 71.5 160.3 79.3 426.3
2012/13 35 107.6 280 80.2 502.8
2018/19 28.8 101 172.4 82.2 384.4

The chart below shows the total annual and spring rainfall for the total data set, 1839 to 2019.

Notice that both total annual and spring rainfall vary over a wide range pretty much for the entire data record. Annual rainfall is mostly in the range 400 to 700 mm per year but fluctuations are the order of the day. There is no “trend”, just chaos. The same applies to the spring totals.

Whenever we hear of a new “meteorological record”, whether it be about temperature or rain, the vibe seems to be one where the “record” provides some legitimacy to the coming “climate change” disaster that has been imminent for around 30 years but has refused to manifest yet. Without some reference to history any story can be blown up out of all proportion and no one is the wiser.

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18 Responses to David Bidstrup: When did we have the driest spring in Adelaide?

  1. Entropy

    I am ashamed to say my first thought was “what a dry shithole!”

  2. mem

    When the BOM says Adelaide has had the driest or Melbourne the hottest I’m always inquisitive as to whether only one weather station is used. For example BOM stated that Melbourne had one of the driest springs in a decade yet where i live which is a north eastern suburb we had 25% more rain than last year and we are only 20 k from the CBD. Some parts of a city fall within wind or rain belts which makes a huge difference to both rainfall and temperature. What are your thoughts?

  3. Roger W

    Ever since the BOM predicted no rain until next April, here in SE Queensland, it hasn’t stopped raining!

  4. Mark M

    Roger W: “Ever since the BOM predicted no rain until next April, here in SE Queensland, it hasn’t stopped raining!”

    Quite so.

    Anyone with a ouija board could predict seasonal heatwaves, drought and bushfires.
    Predicting rain?
    Now we’re talking skill …

    December 11, 2019: There will be no relief for drought-ravaged regions over the summer, with Bureau of Meteorology officials telling a meeting of state and federal ministers there would be no significant rain until at least April.
    https://www.macrobusiness.com.au/2019/12/no-end-for-drought-as-sydney-disappears-into-smoke/

    December 11, 2019: Brisbane weather relief as storm brings six months’ worth of rain in one night
    https://www.abc.net.au/news/2019-12-12/brisbane-storms-damage-six-months-rain/11791512

    Remember the Townsville floods of 2019? Another failure of the BoM to forecast.
    2011 Brisbane floods?

    Fail.

  5. iggie

    Maybe David, they meant the driest spring on record for Australia (and that’s only if you don’t count all the springs before 1900).

  6. Where is 2016 – Adelaide over 800mm of rainfall

    You’ve been litt

  7. Russell

    I tell you BOM are only good for predicting the next 2 days and that’s mostly for the aviation industry (and their longest flights).
    I guess the turkey who said no rain till April hadn’t checked the lastest METARs or he lives in the Climate Change Department on another floor from the professional forecasters at BOM?
    You know, left hand doesn’t know what right hand is doing.
    And remember what Turnbull’s Environmental Minister had to say:

    Mr Hunt said there was no evidence that BoM’s reports were “propaganda”.
    “I’ve had full confidence in what I think is a world-class organisation which is based on hard science, hard data, literally millions of points of information through our satellite and our local monitoring,” he said.

    Yeah right …

  8. Sean

    ‘Statistics quell the extremes of individual observations’

  9. DaveR

    When you say “the presumption is made that the records are factual and not “homogenised” to fit a story” its a good thing you are working with rainfall, not temperatures. The rainfall has been relatively untouched to date – but the temperature data is completely altered.

  10. DaveR

    So the 2018/19 Spring rainfall was the 30th driest of the last 180 years. The driest was in 1895/96, the beginning of the terrible Federation Drought. There are another 4 driest Springs in the Federation Drought in he top 30. You can see the Federation Drought (1896-1903) best in the annual rainfall figures, and there looks like another very dry spell in the 1860s.

    The average annual temperatures in the Federation Drought period were much warmer than today, but only in the original measured raw data. In the BOM homogenised data, they have been significantly reduced across the nation, and are usually excluded from often quoted temperature series, which usually start around 1910, to prevent embarrassment.

  11. Entropy

    December 11, 2019: Brisbane weather relief as storm brings six months’ worth of rain in one night
    https://www.abc.net.au/news/2019-12-12/brisbane-storms-damage-six-months-rain/11791512

    To be fair it was a very small area and storm rain, which is always an anomaly. Things are very crook outside the con urban area of SEQ, and storm rain like that doesn’t matter. This summer will be horrendous for anyone who hasn’t already destocked. You don’t need to be a bureau model morlock to know that.

  12. classical_hero

    Basically we’re experiencing is very similar to the Federation drought. No wonder why they hid the data because it was very hot during that time.

  13. egg_

    I am ashamed to say my first thought was “what a dry shithole!”

    Non.
    Dry as a dead dingo’s d1ck?

  14. egg_

    “what a dry shithole!”

    Long drop toilet?

  15. Rayvic

    David Bidstrup, well done.

  16. Modern recordings of weather data (those that haven’t been fucked around with by activist pricks) have been around for under 200 years.
    This planet has been around for 4.5 billion years.
    Odds that records will be set in one direction or another is a million to one on or shorter.
    Our institutions have been taken over by activist areseholes.

  17. J.H.

    Some may call it Global Warming, but I call it Summer.

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