The Climate and Weather of Australia/Chapter 8

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VIII.—CHIEF CLIMATIC REGIONS.

Our study of the chief weather elements has shown us that Australia has not one general climate, but contains within its vast area several types of climate. They may be classified according to many factors; such as amounts of rainfall, seasons of rainfall dominant winds, topography, &c., &c. A combination of the first two criteria seems to furnish the best primary division, while the less important factors will determine the secondary subdivision.

The proposed scheme may be tabulated as follows:

These subdivisions are shown in Fig. 58.

Monsoon Region.

This comprises the whole of Australia north of the Tropic of Capricorn, together with Southern Queensland and the north of New South Wales, The heaviest rains are in January and February. They are directly due to the indraught caused by the heating of the centre of the continent. This leads to the formation of a locus of low pressure (monsoonal depression) in Northern Australia, and the ascending winds are cooled and deposit their water vapour in heavy rain storms and thunder showers.

Over the greater portion of the area the winter is usually quite dry, and practically the whole of the rain falls in three or four months. But in the east, owing to two special controls, the rain is much more abundant and uniform. Along the Queensland coast the land rises to considerable heights, and there is a very permanent onshore wind the South-east Trade. This leads to a rainfall of over an inch each month in the winter, while the rest of the summer rain region is receiving nothing. It seems worth while therefore to separate this eastern fringe as a subdivision of the summer rain (or monsoon) region.

Meteorological data are given in the following table for type stations in this region:

Station. State. Height. Description.
    Feet.  
Broome Western Australia 63 A coastal town, subject to hurricanes.
Hall's Creek Western Australia 1,225 An inland mining township (200 miles from coast)
Darwin Northern Territory   Capital of Northern Territory (on the coast)
Daly Waters Northern Territory   An inland settlement on Overland Telegraph (300 miles from coast)
Cloncurry Queensland 696 An inland town (200 miles south from Gulf of Carpentaria)
Charleville Queensland 975 A town in South Queensland (300 miles from the Pacific coast)
[1]Harvey Creek Queensland   A coastal town with heaviest rainfall in Australia (25 miles south of Cairns)
Brisbane Queensland 137 Capital of Queensland; in the south-east, about 10 miles up the Estuary
Climatological Regions with Type Stations. Fig. 58.
Climatological Regions with Type Stations. Fig. 58.

Types of the Summer Rain Region.

Pressure.[2]

Station. January. February. March. April. May. June. July. August. September. October. November. December. Year. Number of Years.
Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches.
Broome, Western Australia 29.721 29.731 29.758 29.847 29.920 29.950 29.962 29.951 29.908 29.860 29.792 29.748 29.846 15
Hall's Creek, Western Australia 29.720 29.737 29.787 29.890 29.982 30.012 30.016 29.982 29.916 29.853 29.788 29.742 29.869 12
Darwin, Northern Territory 29.701 29.710 29.746 29.796 29.851 29.881 29.897 29.895 29.864 29.829 29.780 29.727 29.806 31
Cloncurry, Queensland 29.714 29.756 29.823 29.948 30.042 30.077 30.082 30.076 30.009 29.934 29.866 29.783 29.926 12
Charleville, Queensland 29.815 29.874 29.938 30.074 30.169 30.181 30.170 30.165 30.096 30.041 29.950 29.857 30.028  9
Cairns, Queensland 29.752 29.805 29.826 29.923 30.007 30.020 30.028 30.048 30.023 30.003 29.930 29.840 29.934  9
Brisbane, Queensland 29.898 29.927 29.988 30.083 30.138 30.105 30.108 30.138 30.077 30.046 30.003 29.923 30.036 26

Types of the Summer Rain Region.

Temperature.[3]

Station. January. February. March. April. May. June. July. August. September. October. November. December. Year. Number of Years.
° ° ° ° ° ° ° ° ° ° ° ° °
Broome, Western Australia 85.9 85.4 85.4 83.1 76.4 71.2 70.3 72.4 77.0 81.0 84.6 85.9 79.8 16
Hall's Creek, Western Australia 87.0 85.6 82.6 77.7 70.8 65.6 64.7 69.0 76.2 83.4 86.9 87.0 78.0 14
Darwin, Northern Territory 84.0 83.5 84.2 84.2 81.8 77.3 77.2 79.4 83.0 85.2 85.7 85.3 82.6 37
Daly Waters, Northern Territory 86.9 85.5 83.8 80.2 74.7 70.1 68.6 72.7 79.8 86.1 88.2 88.1 80.4 27
Cloncurry, Queensland 87.3 85.0 83.1 77.8 71.0 64.2 61.5 67.0 72.8 82.5 85.2 88.0 77.1 12
Charleville, Queensland 82.9 80.7 76.1 68.7 60.1 53.7 51.1 56.6 62.8 71.6 77.5 80.4 68.5 10
Cairns, Queensland 81.7 81.1 79.7 77.1 73.6 70.5 69.8 70.0 73.0 76.2 78.5 81.3 76.0  8
Brisbane, Queensland 77.2 76.5 74.3 70.2 64.4 60.0 58.0 60.5 65.1 69.8 73.3 76.4 68.8 26

Types of the Summer Rain Region.

Rainfall.

Station. January. February. March. April. May. June. July. August. September. October. November. December. Total for Year. No of Years.
Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches.
Broome, Western Australia  4.96  6.35  3.77  1.35   .41 1.22  .27  .04  .08  .03  .93  3.55  22.96 23
Hall's Creek, Western Australia  5.28  4.73  2.92  1.18   .41  .24  .25  .12  .16  .59 1.36  3.43  20.67 22
Darwin, Northern Territory 15.27 13.05  9.70  4.50   .75  .16  .07  .11  .48 2.12 5.21 10.30  61.72 43
Daly Waters, Northern Territory  6.12  6.71  5.02  1.04   .15  .34  .07  .15  .29  .83 2.15  4.08  26.95 40
Cloncurry, Queensland  4.94  5.07  2.60   .86   .42  .44  .46  .10  .44  .46 1.13  2.99  19.91 23
Charleville, Queensland  2.49  3.14  3.23  1.46  1.41 1.33  .94  .58  .81 1.29 1.34  2.26  20.28 23
Harvey Creek, Queensland 30.87 22.18 32.19 22.20 13.20 7.98 4.22 5.42 3.68 3.81 8.10 11.73 165.58 16
Brisbane, Queensland  6.66  6.63  6.20  3.64  2.92 2.62 2.33 2.35 2.05 2.78 3.65  5.12  46.95 61

Dry Region.

This is bounded somewhat arbitrarily by the 10-in. annual isohyet. Two areas within the tract as plotted have more than 10 inches—in the north-east, the highlands of the MacDonnell Ranges, and in the north-west the Peak Hill Gold-field.

These two relatively wet areas may be related with the two favorite paths of the tropical "lows"; which often curve southward and south-eastward over Pilbara and Western Queensland respectively.

Owing to lack of information the northern boundary of the dry region cannot be accurately plotted, so that the line given—from Winning Pool to Barrow Creek—will, no doubt, need considerable revision later. Although the scattered rains of the north fall chiefly in January, and of the south in May and June, this variation does not determine the type of vegetation which is almost wholly controlled by absence of rain (xerophilous), and not by the season when it falls. The dry region, which consists mainly of an undulating tableland 1,000-3,000 feet high, forms therefore a united whole.

If the isohyets for 0.5 inches are plotted in each month (not shown in Figs. 39 to 50), the MacDonnell Ranges are seen to form an "oasis" in the arid region. In May, June, October, and November, when the districts not only south but east (Sturt's Desert, &c.) are receiving less than half-an-inch this region of uplands (3,000 feet) is favoured by more rainfall. Possibly the Musgrave Ranges—which are said to reach 5,000 feet (Mt. Woodroffe, 5,230 feet), also benefit in a similar degree, but no data are available.

The driest region so far furnished with rain-gauges lies east and north-east from Lake Eyre, where less than 5 inches is the average annual rainfall. This minimum rainfall is coincident with the lowest elevation, Lake Eyre being actually below sea-level, 39 feet.

In the northern moiety of the dry region the temperatures are of course much more severe than in the southern, for, as we have seen, the hottest portion of Australia lies between the Peak Hill and Pilbara Gold-Fields. The evaporation is therefore much greater here than in the southern gold-fields—an important factor in connexion with the water supply of these centres. (Compare Wiluna and Coolgardie in the following table):—

Evaporation Data.

Station. Years. January. February. March. April. May. June. July. August. September. October. November. December. Total Evaporation. Annual Rainfall.
Carnarvon  4 14.6 11.9 10.8  8.3 5.3 4.3 5.0 6.4 7.5 10.0 11.8 13.4 109.3 9.05
Wiluna  8 21.4 17.7 15.7 10.6 7.3 4.7 5.0 6.7 9.5 14.3 18.3 21.7 152.9 9.76
Coolgardie 14 13.1 10.6  9.3  6.2 3.8 2.5 2.5 3.5 5.3  7.5 10.3 13.1 87.74 9.09

N.B.—Coolgardie, 36″ tank with water jacket. Carnarvon and Wiluna, 8″ dishes with small water jacket. No satisfactory determination of the factor required to relate evaporation results from these different experiments has yet been made, but it is possible that the 8″ dish will give the results from 5 to 15 per cent. in excess of those of the tank.

In the following tables, the meteorological data for a number of typical stations in the dry region are given:—

Station. State. Height. Description.
Feet.
Carnarvon Western Australia 15 The driest costal town in Australia.
Nullagine Western Australia 1,265 Inland town (150 miles from coast). Characterized by intense summer heat.
Peak Hill Western Australia 1,930 Inland town (300 miles from coast).
Coolgardie Western Australia 1,389 On the south-east boundary of the dry region (330 miles from coast).
Alice Springs Northern Territory 2,000 In the Central Highlands (600 miles from coast)
William Creek South Australia 250 Near Lake Eyre (250 miles from coast)
Broken Hill New South Wales 1,000 Near the south-west boundary (200 miles from coast)

Types of the Dry Region.

Pressure.[4]

Station. January. February. March. April. May. June. July. August. September. October. November. December. Year. Number of Years.
Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches.
Carnarvon, Western Australia 29.790 29.798 29.848 29.947 30.019 30.038 30.070 30.069 30.030 29.990 29.912 29.822 29.944 15
Nullagine, Western Australia 29.690 29.711 29.787 29.906 29.992 30.042 30.056 30.024 29.944 29.874 29.772 29.704 29.875 13
Peak Hill, Western Australia 29.702 29.726 29.808 29.929 30.023 30.064 30.079 30.051 29.968 29.898 29.792 29.710 29.896 14
Coolgardie, Western Australia 29.866 29.900 29.937 30.106 30.096 30.111 30.024 30.103 30.024 29.974 29.913 29.858 29.999 15
Alice Springs, Northern Territory 29.708 29.736 29.846 29.984 30.072 30.106 30.122 30.056 29.972 29.887 29.804 29.742 29.920 30
Broken Hill, New South Wales 29.875 29.905 29.962 30.120 30.154 30.163 30.114 30.142 30.042 30.030 29.934 29.860 30.025  5


Types of the Dry Region.

Temperatures.[5]

Station. January. February. March. April. May. June. July. August. September. October. November. December. Year. Number of Years.
° ° ° ° ° ° ° ° ° ° ° ° °
Carnarvon, Western Australia 79.8 80.6 79.4 74.7 67.9 62.7 60.6 62.6 65.6 69.0 73.0 76.9 71.1 15
Nullagine, Western Australia 89.8 88.6 84.2 77.3 68.5 61.1 59.3 63.9 71.0 78.2 85.8 88.8 76.4 14
Peak Hill, Western Australia 87.6 86.2 82.1 74.0 63.8 56.5 54.7 58.9 65.0 71.8 80.3 86.2 72.3 14
Coolgardie, Western Australia 77.5 76.0 71.6 65.4 57.6 52.3 50.8 53.4 58.4 63.6 70.9 76.2 64.5 16
Alice Springs, Northern Territory 84.0 82.3 76.9 68.0 59.7 54.2 52.5 58.5 65.5 73.6 79.5 82.5 69.8 34
William Creek, South Australia 82.7 82.5 76.1 67.2 59.2 53.9 52.2 56.2 62.4 70.3 77.1 81.4 68.4 24
Broken Hill, New South Wales 78.4 77.9 71.8 63.9 56.6 51.0 49.2 52.8 58.4 65.8 73.0 76.6 64.6 21

Types of the Dry Region.

Rainfall.

Station. January. February. March. April. May. June. July. August. September. October. November. December. Total for Year. Number of Years.
Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches.
Carnarvon, Western Australia  .30  .70  .45  .52 1.29 2.83 1.87  .63  .25  .08  .04  .09  9.05 30
Nullagine, Western Australia 2.67 2.02 2.60 1.04  .55 1.13  .70  .46  .01  .00  .39 1.17 12.74 15
Peak Hill, Western Australia 1.39 1.06 1.25 1.23 1.01 1.35  .86  .62  .20  .14  .19  .43  9.73 15
Coolgardie, Western Australia  .37  .69  .65  .64 1.35 1.18  .87  .90  .61  .69  .52  .62  9.09 20
Alice Springs, Northern Territory 1.68 1.73 1.24  .90  .60  .57  .46  .40  .41  .72  .90 1.32 10.93 39
William Creek, South Australia  .55  .41  .77  .45  .45  .69  .25  .29  .45  .33  .42  .35  5.41 39
Broken Hill, New South Wales  .76  .84  .63  .72  .87 1.41  .66  .97  .68  .84  .71  .80  9.89 24

Intermediate Region of Uniform Rains.

In our description of the monthly rainfall we saw that the distribution areas were shaped like crescents. The summer rain crescent includes Northern Australia and South-eastern Australia; the winter rain crescent includes South-western Australia and South-eastern Australia. In other words, the two crescents do not meet in the north-west—so far as any but light rains are concerned—but overlap in the south-east. Hence the central coastal aridity in Western Australia, and the region of uniform monthly rainfall in Eastern Australia.

The latter region is a somewhat triangular area reaching from Wilcannia east to the coast at Port Macquarie, and south-east to Albury and thence to Melbourne. A reference to the following tables shows that Dubbo is the typical station, for, as already noted, it has just under 2 inches of rainfall each month of the year. Cobar and Wilcannia to the north-west and Goulburn and Delegate to the south-east are also on the axis of uniformity. To the north-east the summer rains grow proportionately greater—though a considerable amount of rain falls all the winter. To the south-west the June maximum becomes very evident—and West or South-west from the Grampians the winter rainfall is more than double that of summer.

Fig. 59.

Anticyclone causing south-easterly winds and rain in coastal districts of New South Wales.

Furthermore, along the coast from Port Stephens to Ulladulla is an "enclave" of autumn rains. This includes Sydney, and forms a narrow coastal strip with heavy rains in February, March, April, May, and June, and moderate rains in the remaining months. An explanation of this is suggested in the following paragraphs, based on conditions in 1912.

During these autumn months the anticyclones move along latitudes of about 35° S. (In midwinter this path is along 28° and in midsummer along 42°. In Spring the paths are much the same as in autumn.)

About once a week during the autumn months of 1912 this coastal strip experienced rains, while the rest of New South Wales was dry. This rain generally accompanied south-east on-shore winds, in the front and north of a high, as shown in Fig. 59. Out of nineteen examples of this type of rain distribution, in autumn, 1912, no less than fifteen occurred when the "high" was centred about the Bass Straits. (Roughly, between Mt. Gambier and Gabo.)

Meteorological data for the following stations is given in the tables:—

Town. State. Height. Distance
from
Coast.
Description.
    Feet. Miles.  
Wilcannia New South Wales 267 300 An inland town in the Western Plains
Dubbo New South Wales 870 200 On the western slopes of the Divide
Newcastle New South Wales .. .. Coastal town near boundary of uniform regions and autumn rains
Sydney New South Wales 146 .. Capital, on the coast, with autumn maximum
Moruya New South Wales .. .. Coastal town in the south
Yass New South Wales 1,650 100 On the western slopes of the Divide
Kiandra New South Wales 4,640 100 Highest town in Australia
Sale Victoria .. .. Coastal town in drier region of Gippsland
Melbourne Victoria 115 .. Capital, at south-west corner of uniform region
Hobart Tasmania 160 .. Capital, on south-east of island

Types of the Uniform Rain Region.

Pressure.[6]

Station. January. February. March. April. May. June. July. August. September. October. November. December. Year. Number of Years.
Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches.
Wilcannia, New South Wales 29.888 29.920 30.016 30.124 30.177 30.153 30.172 30.147 30.097 30.033 29.984 29.913 30.052 30
Dubbo, New South Wales 29.899 29.935 30.017 30.117 30.173 30.135 30.153 30.144 30.079 30.020 29.958 29.896 30.044 29
Newcastle, New South Wales 29.915 29.961 30.038 30.095 30.107 30.082 30.109 30.103 30.041 30.002 29.974 29.905 30.028 50
Sydney, New South Wales 29.930 29.975 30.051 30.108 30.116 30.080 30.116 30.105 30.045 30.003 29.971 29.916 30.035 51
Moruya, New South Wales 29.908 29.966 30.031 30.056 30.092 30.033 30.069 30.086 29.994 29.960 29.949 29.881 30.002 35
Sale, Victoria 29.879 29.961 30.018 30.050 30.098 30.057 30.042 30.054 29.949 29.918 29.931 29.897 29.988 17
Melbourne, Victoria 29.913 29.962 30.037 30.101 30.106 30.078 30.097 30.067 29.996 29.965 29.952 29.896 30.014 55
Hobart, Tasmania 29.849 29.942 29.969 29.971 30.016 29.974 29.951 29.954 29.866 29.856 29.821 29.819 29.916 28


Types of the Uniform Rain Region.

Temperatures.[7]

Station. January. February. March. April. May. June. July. August. September. October. November. December. Year. Number of Years.
° ° ° ° ° ° ° ° ° ° ° ° °
Wilcannia, New South Wales 81.4 79.9 74.0 65.4 57.7 52.3 50.0 53.9 60.2 68.2 74.8 79.4 66.4 27
Dubbo, New South Wales 78.6 77.0 70.8 64.0 55.2 49.6 47.4 50.6 56.2 63.4 70.9 76.1 62.7 35
Newcastle, New South Wales 73.0 72.4 71.0 66.4 60.3 56.0 54.0 56.2 60.4 64.9 68.6 71.5 64.6 47
Sydney, New South Wales 71.6 71.0 69.2 64.5 58.6 54.3 52.3 54.8 58.8 63.4 67.0 70.0 63.0 54
Moruya, New South Wales 69.0 68.6 67.2 63.2 57.1 53.0 51.8 53.6 56.9 60.2 63.9 66.4 60.9 37
Sale, Victoria 65.8 66.5 63.1 58.4 53.2 49.1 47.5 49.9 52.4 56.0 61.4 64.0 57.3 16
Melbourne, Victoria 67.5 67.3 64.7 59.5 54.1 50.3 48.4 51.0 54.0 57.5 61.3 64.5 58.3 57
Hobart, Tasmania 62.4 62.4 59.5 55.1 50.4 46.8 45.3 47.7 50.8 53.9 57.5 60.3 54.3 42

Types of the Uniform Rain Region.

Rainfall.

Station. January. February. March. April. May. June. July. August. September. October. November. December. Total for Year. No of Years.
Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches.
Wilcannia, New South Wales 0.97 0.83 1.12 0.69 1.04 1.06 0.59 0.84 0.69 0.92 0.68 0.76 10.19 34
Dubbo, New South Wales 2.13 1.87 1.82 1.78 1.87 2.01 1.67 1.83 1.86 1.55 1.78 2.02 22.19 41
Port Macquarie, New South Wales 5.94 7.52 6.52 5.86 5.59 4.63 4.54 3.80 3.95 3.20 4.08 5.87 61.50 42
Sydney, New South Wales 3.67 4.70 5.07 5.24 4.95 5.18 4.68 3.29 2.89 2.82 2.91 2.60 48.00 54
Moruya, New South Wales 3.79 3.32 4.19 3.05 2.77 3.17 2.52 2.29 2.66 2.73 2.30 2.33 35.12 37
Kiandra, New South Wales 4.09 3.15 4.05 4.37 5.27 8.70 6.55 5.95 6.86 6.61 4.90 3.95 64.45 40
Sale, Victoria 2.05 1.52 1.96 1.90 1.83 2.33 1.88 2.01 2.30 2.20 2.14 2.12 24.24 24
Melbourne, Victoria 1.85 1.74 2.18 2.32 2.15 2.11 1.86 1.81 2.35 2.64 2.20 2.30 25.51 57
Hobart, Tasmania 1.80 1.45 1.65 1.80 1.91 2.22 2.10 1.83 2.14 2.24 2.50 1.93 23.57 70

Winter Rain Region.

This region consists of a belt along the south coasts of Australia. It may be subdivided into four sections on geographical grounds, though the meteorology does not differ so much as might be expected—

(1) The south-west corner or Westralia Felix.
(2) The Bight Littoral.
(3) South Australian gulfs, Western Victoria, and the Riverina, New South Wales.
(4) Tasmania (except the south-east).

In these areas there is a strong maximum of rainfall in June, especially in the west. Along the Australian Bight the area receiving more than 10 inches is extremely narrow. The effect of the Flinders Range, which lies athwart the westerly winds, in improving the rainfall of South Australia is very strikingly shown. Probably the long "Rift" Gulf immediately to the west also tends to increase the rainfall hereabouts. In Victoria, the rainfall becomes more uniform towards the north-east.

Along the west coast of Tasmania is a region, unique in Australia, where a superabundance of rain has almost prohibited settlement. There are practically no inhabitants in the south-west region, which is very rugged country covered with an almost impenetrable scrub. The rainfall reaches 115 inches per year on the highlands behind Macquarie Harbor, and is therefore only exceeded at Harvey Creek and neighbouring stations in North Queensland.

Around Hobart is a small region having a much more uniform rainfall with a spring maximum.

Meteorological data for the following stations will indicate how the elements vary in the Winter Rain Region:—

Town. State. Description.
Perth Western Australia Capital. On Melville Water, 10 miles from ocean
Esperance Western Australia On the south coast
Eucla Western Australia On the coast, at the head of the Great Australian Bight
Port Augusta South Australia On the coast, at the head of Spencer's Gulf
Adelaide South Australia Capital. On the east coast of St. Vincent' Gulf
Robe South Australia On the coast, in the south-east corner of South Australia
Albury New South Wales In the Eastern Riverina, 542 feet above sea-level
Launceston Tasmania On the Tamar Estuary, and 30 miles from the sea

Types of the Winter Rain Region.

Pressure.[8]

Station. January. February. March. April. May. June. July. August. September. October. November. December. Year. Number of Years.
Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches.
Perth, Western Australia 29.911 29.927 29.990 30.074 30.079 30.065 30.096 30.088 30.057 30.034 29.994 29.932 30.021 28
Esperance, Western Australia 29.965 29.988 30.028 30.101 30.087 30.036 30.058 30.069 30.012 29.994 29.992 29.958 30.024 16
Eucla, Western Australia 29.924 29.952 30.017 30.087 30.101 30.081 30.110 30.067 30.020 29.981 29.962 29.919 30.018 34
Port Augusta, South Australia 29.874 29.906 29.998 30.102 30.137 30.119 30.148 30.105 30.038 29.983 29.945 29.887 30.020 33
Adelaide, South Australia 29.915 29.952 30.038 30.118 30.125 30.099 30.131 30.100 30.038 29.996 29.973 29.920 30.034 56
Robe, South Australia 29.933 29.978 30.037 30.095 30.127 30.055 30.050 30.058 29.987 29.963 29.971 29.926 30.015 23
Albury, New South Wales 29.883 29.959 30.015 30.084 30.110 30.092 30.097 30.094 30.018 29.969 29.932 29.869 30.010 43
Cape, Otaway, Victoria 29.918 29.965 30.031 30.043 30.075 30.030 30.040 30.011 29.967 29.940 29.934 29.899 29.988 46


Types of the Winter Rain Region.

Temperatures.[9]

Station. January. February. March. April. May. June. July. August. September. October. November. December. Year. Number of Years.
° ° ° ° ° ° ° ° ° ° ° ° °
Perth, Western Australia 73.6 74.2 71.2 66.4 60.4 56.2 55.0 56.0 57.9 60.9 65.4 70.6 64.0 16
Esperance, Western Australia 68.6 69.2 66.7 63.2 58.8 55.1 53.6 54.7 56.8 59.4 63.0 66.3 61.2 16
Eucla, Western Australia 70.9 71.2 69.3 66.1 60.9 55.9 54.3 56.3 59.3 62.7 65.9 69.3 63.5 35
Port Augusta, South Australia 77.5 78.1 73.3 66.3 59.8 54.5 52.8 55.6 60.4 66.7 72.2 75.8 66.1 24
Adelaide, South Australia 74.2 74.0 69.9 63.9 57.7 53.4 51.5 53.8 57.0 61.9 67.1 71.1 62.9 56
Robe, South Australia 64.7 65.0 62.1 58.7 55.6 52.4 50.8 52.0 53.8 56.7 60.1 62.3 57.8 23
Albury, New South Wales 76.2 74.3 69.3 60.4 52.1 47.8 45.9 49.0 53.8 60.1 66.9 71.9 60.7 43
Launceston, Tasmania 64.1 64.5 60.6 55.5 49.1 46.5 44.1 46.3 50.2 53.9 58.2 62.0 54.8 18

Types of the Winter Rain Region.

Rainfall.

Station. January. February. March. April. May. June. July. August. September. October. November. December. Total for Year. No of Years.
Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches. Inches.
Perth, Western Australia  .33  .31  .71 1.65 4.88 6.51 6.44 5.55 3.37 2.06  .76 .54 33.11 37
Esperance, Western Australia  .57  .67  .99 1.51 2.94 4.10 3.99 3.81 2.73 2.15  .97 .84 25.27 29
Eucla, Western Australia  .66  .53  .97 1.20 1.23 1.15  .90  .96  .76  .68  .70 .39 10.13 37
Port Augusta, South Australia  .54  .46  .75  .82 1.15 1.18  .69  .86  .93  .88  .69 .51  9.46 53
Adelaide, South Australia  .73  .60 1.06 1.87 2.74 3.10 2.66 2.50 1.95 1.74 1.15 .94 21.04 74
Robe, South Australia  .80  .65 1.19 1.91 3.04 4.01 3.95 3.62 2.15 1.69 1.07 1.01 24.69 52
Albury, New South Wales 1.44 1.70 2.06 2.12 2.50 3.47 2.77 2.76 2.57 2.71 1.99 1.05 27.75 49
Launceston, Tasmania 2.01 1.14 1.83 2.01 2.58 3.48 2.97 2.75 2.96 2.62 1.79 2.00 28.14 26

Comparison of Climatic Regions.

Each of the four or five main divisions of Australia which have been described in the foregoing can be paralleled by simlar regions in other parts of the world. These are briefly summarized in the following table (based on Herbertson and Koepper):—

Australian. Extra-Australian.
1. Summer rain region Sudan, Brazil (like the wetter north portion); and South Siberia and Argentine (like the drier south-east portion)
1a. North-east coast (trade wind region) Florida, South China coast
2. Dry region Kalahari, Atacama, Sahara, Arizona
3. Uniform rain region Uruguay, Cape Colony (south-east)
3a. Autumn maximum Eastern U.S.A.,Natal, South-east Brazil
4. Winter rain region Cape Colony (west), Chili, California, and Mediterranean lands



Footnotes

  1. N.B.—As pressure and temperature normals are not available for Harvey Creek those for Cairns have been substituted.
  2. Note.—The normals for Queensland stations refer to 9 a.m. observations only; the others are the means of the 9 a.m. and 3 p.m. observations.
  3. The means of maxima and minima.
  4. The normals for Broken Hill refer to 9 a.m. observations only; the others are the means of 9 a.m. and 3 p.m. observations.
  5. The means of maxima and minima.
  6. The normals for New South Wales stations and Hobart refer to 9 a.m. observations only; the Melbourne and Sale normals are the equivalent hourly means deduced from 9 a.m., and 3 p.m., and 9 p.m. observations.
  7. The means of maxima and minima, except for Sale, in which case the normals are the equivalent hourly means deduced from 9 a.m., 3 p.m., and 9 p.m. observations.
  8. The normals for Albury refer to 9 a.m. observations only; those for Cape Otway are equivalent hourly means deducted from 9 a.m., 3 p.m., and 9 p.m. observations, and for the other stations the mean of 9 a.m. and 3 p.m.
  9. The mean of maxima and minima.