Remote Islands and Antarctica in July 2018

Australia's Indian Ocean islands

  • A cool July for Christmas Island, with temperatures more than a degree cooler than average and the lowest July mean temperature since 1994; sea surface temperatures around the Island have also been much cooler than usual
  • Temperatures were slightly average on the Cocos (Keeling) Islands
  • Rainfall below average, with Christmas Island Aero recording only 17.8 mm for the whole month and Cocos Islands Airport recording 96.0 mm
  • Large waves affected the Cocos (Keeling) Islands on the 23rd and 24th, damaging roads, ripping trees from the ground and causing flooding on the south end of West Island

Australia's Pacific Ocean islands

  • Days on Lord Howe Island were about half a degree warmer than average, but nights were around half a degree cooler than average
  • The temperature at Lord Howe Island Aero dropped to 6.1 °C on the morning of the 23rd, the lowest July temperature on record and the second-lowest temperature for any time of year (behind 5.9 °C on 11 September 1992)
  • Rainfall was about three quarters of average on Lord Howe Island
  • Temperatures were above average on Norfolk Island, despite a run of cool mornings from the 20th
  • It was the driest July on record at Norfolk Island Aero, with total rainfall of 30.8 mm well below the July average of around 140 mm

Australia's Antarctic and sub-Antarctic territories

  • It was a cold start to the month for Australia's Antarctic stations: on the 4th, Casey's temperature dropped to -30.0 °C and Davis dropped to -28.0 °C
  • Mawson's temperature dipped to -33.9 °C on the 10th, the lowest for any time of year since May 2012 and the lowest for July since 1998
  • Temperatures rose markedly later in the month: on the 25th Mawson reached -2.8 °C and Davis reached -0.3 °C, both the warmest July temperatures since 2009, and starting an unprecedented run of three July days above -0.5 °C at Davis
  • Casey had its highest July temperature on record with a maximum of +3.0 °C on the 27th (the old site recorded a temperature of +3.5 °C in July 1976)
  • On the 27th, Mawson and Davis both equalled their highest July daily minimum temperature records from 2007
  • Overall, temperatures were more than a degree above average at Mawson, more than three degrees above average at Davis and over four degrees above average at Casey
  • Macquarie Island was almost a degree warmer than average, with fewer cold days and nights than usual for July
  • Rainfall on Macquarie Island was about 120% of the July average

Further information

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Record lowest July total precipitation
New record
(mm)
Old
record
Years of
record
Average for
July
Norfolk Island Aero 30.8 32.8 in 1977 125 139.6



Record highest July temperature
New record
(°C)
Old
record
Years of
record
Average for
July
Casey 3.0 on the 27th 2.4 on the 13th in 2009 30 -10.7



Record highest July daily minimum temperature
New record
(°C)
Old
record
Years of
record
Average for
July
Mawson -5.8 on the 27th = -5.8 on the 6th in 2007 65 -20.9
Davis -3.3 on the 27th = -3.3 on the 5th in 2007 58 -20.7



Record lowest July temperature
New record
(°C)
Old
record
Years of
record
Average for
July
Lord Howe Island Aero 6.1 on the 23rd 6.6 on the 28th in 2010 30 13.9



Record lowest July mean daily minimum temperature
New record
(°C)
Old
record
Years of
record
Average for
July
Christmas Island Aero 21.2 = 21.2 in 1994 43 22.6



Lowest July mean temperature for at least 20 years
Observed
(°C)
Most recent
lower
Average for
July
Christmas Island Aero 23.3 23.2 in 1994 24.4



Summary statistics for July 2018
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Precipitation
(millimetres)
Mean for
July
2018
Diff
from
average
Highest for
July
2018
Mean for
July
2018
Diff
from
average
Lowest for
July
2018
Total for
July
2018
Average
for
July
Rank of
July
2018
Fraction of
July
average
Offshore Islands (district 200)
Christmas Island Aero 25.3 -1.0 26.8 1st 21.2 -1.4 18.9 14th 17.8 96.7 low 18%
Cocos Island Airport 28.6 +0.5 30.0 1st 24.4 +0.4 22.0 16th 96.0 210.8 low 46%
Lord Howe Island Aero 19.5 +0.5 21.5 6th 13.3 -0.6 6.1 23rd 106.6 137.8 average 77%
Norfolk Island Aero 19.4 +1.0 21.1 1st 14.1 +0.5 11.9 27th 30.8 139.6 lowest 22%
Antarctica and Macquarie Island (district 300)
Casey -6.9 +3.8 3.0 27th -14.0 +5.0 -30.0 4th 6.8 26.7 v low 25%
Davis -10.7 +3.6 -0.3 25th -17.3 +3.4 -28.0 4th 12.2 8.3 high 147%
Macquarie Island 5.8 +0.9 7.9 3rd 2.6 +1.0 -0.9 10th 89.0 74.4 high 120%
Mawson -13.2 +1.8 -2.8 25th -19.7 +1.2 -33.9 10th
Note: Precipitation values from Casey and Davis should be used with caution.

Daily maximum temperatures for July 2018
Offshore Islands (200)12345678910111213141516171819202122232425262728293031
Christmas Island Aero26.826.526.025.526.024.324.826.025.425.425.324.924.924.924.925.025.324.525.724.525.125.323.925.425.325.425.525.924.524.926.0
Cocos Island Airport30.029.629.529.428.228.328.828.529.229.029.529.329.228.627.827.827.428.628.328.628.328.928.228.428.427.628.829.527.228.128.3
Lord Howe Island Aero20.517.718.820.320.521.519.918.418.618.218.819.518.318.217.820.319.020.720.521.318.017.918.120.021.420.520.819.720.519.419.4
Norfolk Island Aero21.118.718.118.718.318.019.321.020.418.718.218.920.020.520.320.119.319.118.620.220.317.518.218.119.119.119.919.720.520.320.0
Antarctica and Macquarie Island (300)12345678910111213141516171819202122232425262728293031
Casey-17.7-23.7-22.8-13.8-7.4-7.4-6.4-4.3-9.0-8.3-8.7-7.1-6.8-5.3-4.4-5.5-4.8-2.5-4.8-3.1-3.40.5-0.60.01.42.63.0-11.1-9.2-15.8
Davis-12.6-20.4-23.7-18.1-19.3-20.9-20.5-20.9-17.3-17.7-11.2-10.5-9.1-13.6-14.3-17.4-16.0-8.3-5.5-1.2-2.2-5.8-5.2-3.8-0.3-0.4-0.4-5.5-2.6-2.2-4.0
Macquarie Island5.77.97.97.07.07.06.94.05.16.16.55.83.74.25.86.67.06.26.26.02.74.05.85.76.76.24.24.36.06.05.5
Mawson-12.3-17.2-15.7-15.5-19.2-23.1-24.6-24.1-27.1-18.0-14.0-19.9-15.5-16.3-20.1-14.4-10.4-12.1-14.7-8.8-10.1-8.6-9.4-4.6-2.8-3.1-3.4-4.4-6.6-6.7-6.3
Values are the maximum temperature, usually in the 24 hours from 9 am on the day indicated,
and typically occurred in the afternoon of that day.
Temperatures coloured according to their difference
from the long-term average for the period
-10.0 -9.0 -8.0 -7.0 -6.0 -5.0 -4.0 -3.0 -2.0 -1.0 0.0 +1.0 +2.0 +3.0 +4.0 +5.0 +6.0 +7.0 +8.0 +9.0 +10.0 °C Grey outline marks highest
and lowest for the period

Daily minimum temperatures for July 2018
Offshore Islands (200)12345678910111213141516171819202122232425262728293031
Christmas Island Aero22.722.521.922.522.222.220.022.322.522.322.121.921.418.920.320.920.920.520.221.420.521.819.920.521.420.821.321.820.119.221.2
Cocos Island Airport27.026.826.625.223.823.124.024.824.523.724.126.426.123.323.022.022.623.023.224.125.525.824.924.923.722.223.725.924.123.524.7
Lord Howe Island Aero10.615.315.516.017.718.218.215.314.513.08.414.014.813.512.810.813.615.38.914.314.813.06.17.516.713.312.013.47.916.210.6
Norfolk Island Aero15.214.915.815.214.514.713.216.415.115.512.512.715.316.416.213.712.913.915.512.912.814.512.613.112.612.411.913.113.612.815.7
Antarctica and Macquarie Island (300)12345678910111213141516171819202122232425262728293031
Casey-20.7-26.7-29.9-30.0-26.4-16.6-15.8-14.1-11.4-16.5-12.3-13.0-14.7-13.7-11.6-10.2-12.7-8.4-6.6-9.0-8.1-7.7-7.6-7.7-10.8-4.5-4.5-11.9-17.8-18.2
Davis-27.4-20.5-25.9-28.0-25.3-21.8-25.3-24.5-25.1-24.8-25.3-24.7-14.5-14.0-17.9-21.1-25.0-23.5-20.3-9.5-6.3-6.4-13.3-13.3-7.5-5.1-3.3-6.2-10.8-13.4-6.1
Macquarie Island3.43.25.6-0.32.23.84.82.91.4-0.90.01.32.10.32.03.74.94.24.82.81.40.00.63.64.95.63.40.50.53.53.4
Mawson-18.6-20.1-22.0-22.0-23.9-26.4-28.0-31.2-30.0-33.9-32.5-24.1-24.9-23.9-23.5-27.6-25.2-16.1-20.5-21.1-18.3-13.1-13.9-11.6-11.7-7.0-5.8-5.9-9.7-9.8-9.6
Values are the minimum temperature, usually in the 24 hours to 9 am on the day indicated,
and typically occurred that morning.
Temperatures coloured according to their difference
from the long-term average for the period
-10.0 -9.0 -8.0 -7.0 -6.0 -5.0 -4.0 -3.0 -2.0 -1.0 0.0 +1.0 +2.0 +3.0 +4.0 +5.0 +6.0 +7.0 +8.0 +9.0 +10.0 °C Grey outline marks highest
and lowest for the period

Daily precipitation for July 2018
Offshore Islands (200)12345678910111213141516171819202122232425262728293031
Christmas Island Aero - - - - - - 2.8 0.2 - - - - - 9.2 0.2 - - 1.2 1.8 0.2 - - 0.4 0.4 0.2 - - - 0.2 1.0 -
Cocos Island Airport - - - 2.4 9.8 11.2 7.8 - 7.2 2.8 8.4 - - 0.2 - 11.0 6.4 1.2 5.6 1.0 - - 0.2 0.2 - 0.2 1.2 0.4 2.4 16.4 -
Lord Howe Island (Milky Way) 0.2 0.8 8.0 6.6 0.2 - 0.6 23.4 2.4 0.4 0.2 1.6 16.4 21.0 4.0 - 1.2 - 0.2 - 10.2 1.2 - 0.2 - - - 17.2 0.2 2.6 1.0
Lord Howe Island Aero 0.4 0.8 8.6 4.2 - - 1.0 17.4 1.2 0.4 1.2 0.4 16.2 20.0 0.6 - 1.4 - - - 11.8 0.6 - 1.0 - - - 16.4 - 2.4 0.6
Norfolk Island Aero - 0.2 2.0 0.2 0.2 - - - - - - 0.2 - 8.8 - - - 10.2 0.2 - 1.2 3.6 - 0.2 - - 3.6 0.2 - - -
Antarctica and Macquarie Island (300)12345678910111213141516171819202122232425262728293031
Casey - 0.6 - - - - - 0.6 2.6 - - -


- - 0.4 2.2 0.4

- - - - - - - -
Davis
- - - - - - - - 2.6 0.4 - 1.4 1.6 - 0.8 - - 0.6 0.4 - 4.4 - - - - - - - - -
Macquarie Island 4.2 0.2 9.4 8.4 4.2 0.8 5.0 1.8 1.4 1.8 4.4 0.8 3.4 1.0 0.2 7.6 6.0 0.2 1.6 10.4 1.0 - 0.2 - 0.6 2.4 2.8 1.0 0.6 3.6 4.0
Most values are the precipitation in the 24 hours to 9 am on the day indicated. Days marked with → are part of a longer accumulation, which is shown on the final day.
Values over 100 mm have been rounded to the nearest whole millimetre.
Days marked with - have a precipitation report of zero; days left blank have no precipitation report (which often indicates no precipitation fell).
Precipitations coloured
according to the amount
0 1.0 5.0 10.0 15.0 25.0 50.0 100 150 200 300 400 600 millimetres

Map of the areas covered by this summary

Notes

The Monthly climate summary, generally published on the first working day of each month, lists the main features of the weather in Remote Islands and Antarctica using the most timely and accurate information available on the date of publication; it will generally not be updated. More extensive discussion of significant weather events, along with later information and data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review.

This statement has been prepared based on information available at 3 pm on Wednesday 1 August 2018. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

In some situations, some or all of the precipitation is in the form of hail or snow. In these cases the totals given are for the water equivalent: the depth of liquid water that results from melting any frozen precipitation. There can be significant 'undercatch' of snow in strong winds, meaning the true precipitation can be higher than that reported.

Averages for individual sites are long-term means based on observations from all available years of record, which vary widely from site to site. They are not shown for sites with less than 10 years of record, as they cannot then be calculated reliably.
The median is sometimes more representative than the mean of long-term average precipitation.

The Rank indicates how precipitation this time compares with the climate record for the site, based on the decile ranking (very low precipitation is in decile 1, low in decile 2 or 3, average in decile 4 to 7, high in decile 8 or 9 and very high is in decile 10).
The Fraction of average shows how much precipitation has fallen this time as a percentage of the long-term mean.

Where temperature area averages are mentioned, they are derived from the ACORN-SAT dataset.

Further information

Media
(03) 9669 4057
Enquiries