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Ian Hill: There have only been 78 other heatwaves like that in Adelaide… and 51 were hotter

Posted By Joanne Nova On January 6, 2012 @ 2:02 am In Global Warming | Comments Disabled

It’s another mindless record used to remind the public to “keep the faith” and recite the litany:

“Adelaide had it’s hottest start to the year since 1900″ Sky news

Picking three particular days  outof 365 and comparing them over a century is about as cherry-pickingly meaningless as it gets. But Ian Hill went back through the records to find that not only have there been 79 heatwaves in Adelaide since 1887, but there have been 51 heat-waves that were hotter since 1887.

Ian Hill crunched the numbers and wrote:

Using the definition of a heatwave being “three or more consecutive days at or above 38C”, for no other reason than the fact that this fits in nicely with Adelaide’s recent maxima of 38.0, 41.6 and 40.6 on Dec 31, Jan 1 and Jan 2 respectively, I found that there have been 79 such heatwaves recorded in Adelaide since Jan 21, 1887, the date of the first such information available from the BOM. The recent heatwave is ranked 52nd, where the average maximum of days involved is used to rank heatwaves of the same duration.

If the file is sorted in chronological order a familiar trend emerges where there are many years on end with no heatwaves, then clusters of them. Between 1973 and 1989 there was only one, a week-long heatwave in January 1982. The longest heatwave was in March 2008 where there were 12 consecutive days above 38 degrees C. In fact the day before was 37.9 and the previous two days to that were above 35, so it was reported as a 15-day heatwave. This would be the true “record” for many sites in SE Australia and for Adelaide it was called “a once in 3000 years occurrence”.

Probably the most severe heatwaves were in January 1908 where the Adelaide citizens endured a week of temperatures averaging 43.2. Earlier in the month they had six days averaging 41.8.

The Adelaide data comes from two BOM sites, West Terrace until 1976 and then Kent Town, 2km to the east. As far as I’m concerned there’s not much difference between them for the purposes of this exercise.

Regards

Ian

UPDATE: Someone has taken this nice data and done good graphs of Adelaide Heatwaves.

—————————————

Heatwaves in Adelaide

Definition: Three or more days at or above 38C
Observations: West Terrace site prior to 1977. Kent Town from 1977.

Date

Rank

Date ended

Days

Ave max

order

1

Mar 17, 2008

12

39.342

75

2

Jan 19, 1908

7

43.243

23

3

Feb 2, 2009

7

42.271

76

4

Jan 24, 1982

7

40.843

58

5

Mar 13, 1934

7

40.743

40

6

Mar 13, 1940

7

40.600

44

7

Jan 7, 1908

6

41.750

22

8

Jan 14, 1927

6

41.367

35

9

Feb 13, 1899

6

41.267

12

10

Jan 19, 1934

6

39.717

39

11

Feb 22, 1997

6

39.367

64

12

Nov 15, 2009

6

39.150

77

13

Jan 10, 1939

5

42.860

42

14

Dec 30, 1897

5

40.580

8

15

Feb 4, 1898

5

40.540

9

16

Feb 13, 1939

5

40.060

43

17

Jan 6, 1906

4

43.950

19

18

Feb 3, 1912

4

43.300

28

19

Jan 13, 1905

4

42.925

18

20

Jan 29, 1943

4

42.200

47

21

Jan 3, 1900

4

41.850

13

22

Jan 11, 2010

4

41.775

78

23

Jan 22, 2006

4

41.475

72

24

Jan 12, 1889

4

41.300

2

25

Mar 4, 1942

4

41.300

46

26

Jan 19, 1959

4

41.000

50

27

Jan 1, 2008

4

40.925

74

28

Dec 31, 1898

4

40.575

11

29

Jan 25, 1921

4

40.525

32

30

Jan 28, 1961

4

40.375

52

31

Feb 3, 1993

4

40.125

63

32

Jan 21, 1973

4

39.750

57

33

Feb 15, 1895

4

39.500

7

34

Jan 25, 2001

4

39.300

68

35

Mar 3, 1989

4

38.825

59

36

Jan 28, 1900

3

42.333

14

37

Jan 22, 1889

3

42.067

3

38

Jan 9, 1930

3

41.867

36

39

Jan 31, 1968

3

41.700

54

40

Feb 15, 2004

3

41.667

71

41

Feb 19, 1914

3

41.633

29

42

Nov 30, 1922

3

41.467

34

43

Jan 1, 1905

3

41.300

17

44

Nov 26, 1894

3

41.200

6

45

Nov 23, 1888

3

41.067

1

46

Jan 3, 1991

3

40.867

61

47

Dec 24, 1920

3

40.800

31

48

Jan 6, 1999

3

40.400

66

49

Jan 19, 1901

3

40.333

15

50

Feb 18, 1892

3

40.300

4

51

Feb 10, 1930

3

40.100

37

52

Jan 2, 2012

3

40.067

79

53

Jan 16, 1960

3

40.033

51

54

Feb 17, 1916

3

39.967

30

55

Feb 4, 2000

3

39.967

67

56

Mar 2, 1893

3

39.933

5

57

Dec 26, 1941

3

39.933

45

58

Dec 9, 1906

3

39.900

20

59

Feb 8, 1970

3

39.900

55

60

Jan 6, 1910

3

39.867

25

61

Feb 4, 1991

3

39.767

62

62

Feb 21, 1910

3

39.700

27

63

Dec 17, 2002

3

39.667

70

64

Feb 5, 2007

3

39.633

73

65

Feb 12, 1921

3

39.600

33

66

Feb 17, 1910

3

39.533

26

67

Feb 1, 1903

3

39.467

16

68

Mar 8, 1989

3

39.433

60

69

Feb 25, 1907

3

39.400

21

70

Dec 7, 1908

3

39.367

24

71

Feb 17, 1971

3

39.233

56

72

Feb 24, 1898

3

39.167

10

73

Jan 31, 1951

3

39.167

49

74

Feb 20, 2001

3

39.100

69

75

Dec 7, 1950

3

39.067

48

76

Mar 4, 1930

3

39.033

38

77

Feb 25, 1935

3

38.767

41

78

Feb 26, 1998

3

38.733

65

79

Feb 6, 1967

3

38.600

53

 

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