Remote Islands and Antarctica in December 2018

Australia's Indian Ocean islands

  • Temperatures were below average on the Cocos (Keeling) Islands for most of the month, with the minimum at the airport of 20.4 °C on the morning of the 20th the lowest December temperature on record
  • Cocos Islands Airport's mean daily maximum temperature of 28.9 °C was only half a degree below average, but the lowest since 1992
  • Most of the month's 84 mm of rainfall on the Cocos (Keeling) Islands fell overnight from the 15th into the 16th
  • Daytime temperatures on Christmas Island were close to or below average for most of the month, but some warm weather in the final week resulted in the mean being a little above average
  • There were some unusually cool nights on Christmas Island in the second half of the month, with a minimum of 17.1 °C on the morning of the 20th the lowest December temperature on record
  • Problems with the automated observing equipment at Christmas Island airport meant data from the final few days of the month are missing and the rainfall total is uncertain: there had been only 2.4 mm up to 9 am on the 28th (well down on the December average of 220 mm)

Australia's Pacific Ocean islands

  • There were many cool days on Lord Howe Island, but warm weather around the 20th and again in the final days of the month meant overall the month was a little warmer than average
  • With only 7.8 mm of rainfall for the whole month (much falling around the 22nd), well down on the December average and Lord Howe Island Airport's driest December on record, although other sites on the island had somewhat more rain
  • Temperatures were above average on Norfolk Island, despite rather cool mornings on the 12th and 19th
  • Norfolk Island Airport reported only 7.2 mm of rainfall for the whole month, the second-driest December on record (records go back to 1891)

Australia's Antarctic and sub-Antarctic territories

  • Cold weather was dominant in the first half of the month at Mawson and Davis, while at Casey there were also some cold days in the final week
  • Overall, Mawson and Casey were a little cooler than average for December, but a spell of mild days gave Davis a mean maximum temperature above average
  • Macquarie Island had a very warm month: the highest December mean daily maximum temperature on record, the third-warmest December for mean daily minimum temperatures and the second-warmest (behind 2005) for overall mean temperature
  • Total precipitation on Macquarie Island was a little below average

Further information

Media
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Record lowest December total precipitation
New record
(mm)
Old
record
Years of
record
Average for
December
Lord Howe Island Aero 7.8 24.6 in 2009 31 102.9

Lowest December total precipitation for at least 20 years
Observed
(mm)
Most recent
lower
Average for
December
Norfolk Island Aero 7.2 5.2 in 1899* 85.9

* note: there are gaps in the historical record at this site, so it is possible a lower value has gone unreported




Record highest December mean daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
December
Macquarie Island 10.2 9.9 in 2005 70 7.9



Lowest December mean daily maximum temperature for at least 20 years
Observed
(°C)
Most recent
lower
Average for
December
Cocos Island Airport 28.9 28.5 in 1992 29.4



Record lowest December temperature
New record
(°C)
Old
record
Years of
record
Average for
December
Cocos Island Airport 20.4 on the 27th 21.1 on the 9th in 1960 67 24.6
Christmas Island Aero 17.1 on the 20th 18.0 on the 7th in 1985 46 22.6



Summary statistics for December 2018
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Precipitation
(millimetres)
Mean for
December
2018
Diff
from
average
Highest for
December
2018
Mean for
December
2018
Diff
from
average
Lowest for
December
2018
Total for
December
2018
Average
for
December
Rank of
December
2018
Fraction of
December
average
Offshore Islands (district 200)
Christmas Island Aero 28.0 +0.2 30.1 25th 22.1 -0.5 17.1 20th   219.9    
Cocos Island Airport 28.9 -0.5 30.6 29th 24.5 -0.1 20.4 27th 84.0 117.9 average 71%
Lord Howe Island Aero 24.3 +0.2 27.4 21st 19.5 +0.2 12.0 4th 7.8 102.9 lowest 8%
Norfolk Island Aero 23.9 +0.5 26.9 23rd 18.5 +0.7 15.1 12th 7.2 85.9 v low 8%
Antarctica and Macquarie Island (district 300)
Casey 1.3 -0.2 4.3 23rd -3.7 -0.1 -8.2 9th 16.0 13.2 average 121%
Davis 3.1 +0.6 7.1 21st -2.4 -0.3 -6.3 1st        
Macquarie Island 10.2 +2.3 11.6 12th 6.0 +1.7 2.8 21st 71.8 80.5 average 89%
Mawson 2.0 -0.1 5.5 29th -3.8 -0.5 -7.1 4th
Note: Precipitation values from Casey and Davis should be used with caution.

Daily maximum temperatures for December 2018
Offshore Islands (200)12345678910111213141516171819202122232425262728293031
Christmas Island Aero27.427.628.128.427.527.926.528.127.528.627.527.927.527.227.828.128.527.627.428.128.328.127.728.630.129.729.3
Cocos Island Airport28.528.828.628.828.729.129.228.428.628.628.328.929.428.428.027.929.127.028.328.528.728.928.929.529.028.929.129.430.630.430.3
Lord Howe Island Aero23.025.123.724.322.121.621.123.122.923.624.123.623.824.524.824.225.025.626.427.127.425.123.323.223.624.124.725.626.125.726.3
Norfolk Island Aero23.323.324.123.125.621.721.522.522.322.521.922.524.124.624.224.424.323.824.224.825.125.926.923.723.723.923.924.524.524.824.5
Antarctica and Macquarie Island (300)12345678910111213141516171819202122232425262728293031
Casey1.81.4-1.9-2.4-0.1-0.6-1.8-0.30.70.60.90.22.22.2-0.30.71.83.93.73.82.73.24.32.31.51.11.31.62.12.40.3
Davis0.52.41.40.82.52.10.70.12.21.81.02.22.03.22.92.43.43.73.75.07.16.15.54.46.15.13.84.83.53.42.9
Macquarie Island10.99.610.711.211.09.39.911.510.410.110.011.610.610.610.710.79.69.410.110.09.610.08.910.09.99.59.510.011.48.410.1
Mawson-0.80.80.50.21.6-0.11.0-1.31.60.81.32.82.2-1.11.62.71.33.21.33.74.53.72.92.53.94.13.55.15.51.91.7
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 December 2018
Offshore Islands (200)12345678910111213141516171819202122232425262728293031
Christmas Island Aero22.220.821.823.423.323.824.223.923.823.923.823.022.323.022.122.922.723.121.717.118.519.320.221.620.821.721.521.1
Cocos Island Airport25.024.624.824.024.025.225.825.425.524.924.525.525.825.724.723.925.024.324.524.324.424.223.425.023.222.720.423.723.326.725.4
Lord Howe Island Aero19.319.821.812.018.418.017.618.519.819.415.420.513.021.421.521.121.321.220.120.722.223.720.218.717.516.019.921.021.521.722.0
Norfolk Island Aero19.318.319.320.918.718.817.017.217.417.817.215.116.918.418.117.819.219.115.918.220.520.521.718.517.518.918.118.819.019.019.5
Antarctica and Macquarie Island (300)12345678910111213141516171819202122232425262728293031
Casey-2.5-3.5-4.4-5.5-4.3-4.6-3.7-4.0-8.2-4.7-6.0-2.5-3.0-1.8-3.2-2.9-5.0-2.3-0.8-0.2-0.7-2.0-3.8-4.9-5.7-3.6-3.9-6.3-1.9-3.1-5.0
Davis-6.3-4.1-4.0-5.8-5.0-3.9-4.5-4.1-3.4-3.3-3.2-4.0-2.0-2.6-1.4-1.90.0-0.6-2.4-0.10.3-0.40.5-1.1-1.4-2.9-0.9-1.8-1.6-1.4-1.0
Macquarie Island7.27.36.46.93.06.67.05.77.46.06.87.97.96.27.76.14.04.55.37.02.84.27.36.06.14.34.07.47.35.92.9
Mawson-5.7-4.8-6.6-7.1-5.4-3.9-4.7-5.0-6.0-5.4-4.3-4.8-4.5-4.4-3.8-2.1-4.1-2.2-2.3-2.6-2.5-1.8-1.8-2.8-3.1-2.1-3.4-3.9-1.5-3.5-2.4
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 December 2018
Offshore Islands (200)12345678910111213141516171819202122232425262728293031
Christmas Island Aero 1.0 - - - - - - 0.4 0.6 - - - - - 0.4 - - - - - - - - - - - - -
Cocos Island Airport - -
3.4 0.2 - - - - - - - - - 2.0 65.8 1.4 3.0 0.6 - - 0.8 3.8 - - - - 1.6 1.4 - -
Lord Howe Island (Middle Beach) 0.2 - - - - - - - - - - - - - - - - - - 0.4 0.8 0.8 9.0 0.6 - - - - - - -
Lord Howe Island (Milky Way) 0.2 - - - - - - - - - - 0.2 - - - - - - - - 0.6 1.0 9.6 0.4 - - - - - - -
Lord Howe Island (Orlando) - - 2.0 - - - - - - - - - - - - - - - - 4.0 - 1.0 3.0 1.0 - - - - - - -
Lord Howe Island Aero 0.2 - - - - - - - - - - - 0.2 - - - - - - 1.8 0.8 0.6 3.6 0.6 - - - - - - -
Norfolk Island Aero - - - 0.2 0.4 - - - - - - - - - - - - - - - - 0.2 - 1.4 5.0 - - - - - -
Antarctica and Macquarie Island (300)12345678910111213141516171819202122232425262728293031
Casey 2.2 - - 6.0 - - - - - - - - - - - 5.0 1.8
- -


- - - 1.0 - - - -
Davis - - - - - - -
- - - - - - - - -
- - - - - - - - - - -
-
Macquarie Island - 0.4 1.4 - 0.4 0.6 11.4 - 0.4 0.2 0.6 0.2 - 0.6 1.8 - 0.6 0.6 0.2 - 2.2 2.6 5.8 10.6 1.2 2.0 5.2 4.4 2.4 15.6 0.4
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 4 pm on Tuesday 8 January 2019. 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