Remote Islands and Antarctica in December 2021

Australia's Indian Ocean islands

  • Christmas Island Aero recorded 103 mm on the 19th, its wettest day since May and wettest December day since 2017.
  • The December rainfall total for Christmas Island Aero was 401 mm, which was 76% above average.
  • In contrast, Cocos Island Airport recorded little rainfall during the month, resulting in a monthly total that was only about one third of its December average.
  • At Christmas Island Aero and Cocos Island Airport, mean maximum and mean minimum temperatures were warmer than average.

Australia's Pacific Ocean islands

  • Norfolk Island Aero recorded 53 mm during the month, which was only 63% of its December average.
  • The mean minimum temperature at Norfolk Island Aero was 20.4 °C, which was 2.5 °C warmer than average and the highest December mean daily minimum temperature on record for this site.
  • Norfolk Island Aero had its highest December mean daily maximum temperature since 1997.
  • Lord Howe Island Aero had a monthly rainfall total of 116 mm, which was 15% above its December average.
  • At Lord Howe Island, mean maximum and mean minimum temperatures were close to one degree warmer than average.

Australia's Antarctic and sub-Antarctic territories

  • Total monthly wind run was above average at Davis and Casey, but below average at Mawson.
  • The strongest wind gust recorded during this month was 165 km/h at Mawson station on the 5th, which was the strongest wind gust in December since 2007 for this site.
  • The coldest temperature recorded during the month was −7.8 °C at Mawson station on the 2nd.
  • Both mean maximum and mean minimum temperatures were above the December average at each of the Australian Antarctic stations.
  • Precipitation at Macquarie Island was recorded on most days of the month, and total monthly precipitation was 22% above the December average.
  • Macquarie Island was warmer than average for December, and on the 2nd reached 10 °C for the first time since March.
  • The strongest wind gust recorded at Macquarie Island this month was 113 km/h on the 19th, due to approaching low pressure system and the associated cold front.

Further information

Media
(03) 9669 4057

Highest December mean daily maximum temperature for at least 20 years
Observed
(°C)
Most recent
higher
Average for
December
Norfolk Island Aero 24.8 25.2 in 1997 23.4



Record highest December mean daily minimum temperature
New record
(°C)
Old
record
Years of
record
Average for
December
Norfolk Island Aero 20.4 20.1 in 1997 82 17.9



Highest December mean temperature for at least 20 years
Observed
(°C)
Most recent
higher
Average for
December
Norfolk Island Aero 22.6 22.7 in 1997 20.7



Summary statistics for December 2021
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Precipitation
(millimetres)
Mean for
December
2021
Diff
from
average
Highest for
December
2021
Mean for
December
2021
Diff
from
average
Lowest for
December
2021
Total for
December
2021
Average
for
December
Rank of
December
2021
Fraction of
December
average
Offshore Islands (district 200)
Christmas Island Aero 28.1 +0.3 29.8 28th 23.0 +0.4 21.0 10th 400.6 227.3 high 176%
Cocos Island Airport 29.7 +0.3 31.2 12th 25.3 +0.7 23.3 11th 40.6 116.4 low 35%
Lord Howe Island Aero 24.9 +0.8 27.2 10th 20.2 +0.9 18.4 16th 115.6 100.6 average 115%
Norfolk Island Aero 24.8 +1.4 26.7 12th 20.4 +2.5 18.0 1st 53.2 84.7 average 63%
Antarctica and Macquarie Is. (district 300)
Casey 1.9 +0.4 6.0 18th -2.6 +1.1 -6.1 7th 6.0 12.7 average 47%
Davis 2.7 +0.2 8.9 19th -1.5 +0.7 -4.8 1st 0.8 1.9 average 42%
Macquarie Island 8.5 +0.5 10.8 2nd 4.7 +0.4 2.0 11th 99.0 81.1 high 122%
Mawson 2.4 +0.3 6.8 19th -2.9 +0.4 -7.8 2nd
Note: Precipitation values from Casey and Davis should be used with caution.

Daily maximum temperatures for December 2021
Offshore Islands (200)12345678910111213141516171819202122232425262728293031
Christmas Island Aero28.728.324.825.526.329.325.127.728.829.229.028.028.128.428.128.028.028.026.127.528.127.728.928.529.028.229.529.829.229.229.4
Cocos Island Airport29.729.529.529.129.829.529.629.130.230.030.431.230.230.330.230.330.529.830.030.429.830.530.627.327.228.329.430.2
Lord Howe Island Aero23.424.925.325.324.123.925.025.725.727.225.724.623.224.723.423.424.325.125.426.726.826.526.625.424.025.325.723.223.523.524.7
Norfolk Island Aero24.924.223.624.424.924.324.525.525.124.925.226.723.924.524.824.724.624.025.224.025.124.925.524.925.826.225.523.423.624.224.6
Antarctica and Macquarie Is. (300)12345678910111213141516171819202122232425262728293031
Casey1.43.64.60.52.90.51.2-0.9-0.40.0-0.51.83.03.13.45.85.96.05.22.20.90.10.81.20.70.20.30.31.11.32.0
Davis0.11.02.82.41.43.04.01.01.80.31.21.92.83.82.73.22.56.78.94.43.84.25.75.22.81.00.51.30.40.92.4
Macquarie Island8.810.88.49.38.29.09.86.57.67.77.09.58.59.59.59.47.08.47.69.68.69.97.78.89.710.16.75.87.18.67.1
Mawson2.4-0.91.7-0.91.40.50.30.31.72.63.12.32.93.62.11.23.52.86.84.11.73.55.23.64.42.01.62.62.02.92.2
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 2021
Offshore Islands (200)12345678910111213141516171819202122232425262728293031
Christmas Island Aero23.423.422.822.521.823.222.322.023.221.021.623.324.024.124.223.423.824.322.822.724.522.023.323.022.222.823.222.522.923.424.3
Cocos Island Airport25.824.825.624.624.525.124.723.623.924.623.326.726.726.826.425.425.725.526.025.926.426.425.724.924.224.624.025.9
Lord Howe Island Aero20.721.419.120.619.719.920.021.621.719.420.020.020.319.220.518.420.019.021.322.120.022.220.522.819.920.019.620.019.118.518.7
Norfolk Island Aero18.020.220.521.121.121.320.721.421.421.321.922.022.519.320.120.319.518.718.620.721.719.819.618.620.319.820.221.120.419.619.2
Antarctica and Macquarie Is. (300)12345678910111213141516171819202122232425262728293031
Casey-1.6-3.0-4.3-2.7-3.1-5.9-6.1-3.9-3.1-2.3-2.6-2.9-1.3-0.3-0.4-0.6-1.4-1.8-3.1-0.6-3.2-3.9-3.3-1.9-1.9-2.1-1.3-2.7-4.0-2.9-3.5
Davis-4.8-3.4-3.3-1.0-1.0-1.5-1.4-0.7-1.3-1.2-2.1-2.6-0.3-0.5-2.6-0.4-1.0-2.01.20.0-0.1-0.6-0.1-0.8-1.6-2.1-1.7-1.6-2.5-3.0-1.8
Macquarie Island4.76.95.96.32.84.07.26.42.34.42.03.65.85.96.66.34.74.25.86.25.14.43.82.75.85.62.83.23.12.25.3
Mawson-7.5-7.8-3.6-3.4-3.4-2.3-2.1-2.2-2.7-2.7-4.9-3.5-4.9-0.7-1.6-4.5-2.7-1.1-1.80.7-1.7-2.4-0.6-2.4-0.1-2.0-2.5-1.9-3.9-3.7-5.6
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 December 2021
Offshore Islands (200)12345678910111213141516171819202122232425262728293031
Christmas Island Aero 0.2 1.4 9.4 10.2 35.0 6.8 79.0 63.2 - - - - - - 0.4 - 103 35.2 13.6 0.4 15.2 1.4 8.2 - 2.4 14.2 1.6 -
Cocos Island Airport - 4.6 - 0.8 0.6 - - - - -
- 0.6 - - - - - - - -
- 9.4

5.0 6.8
7.6 5.2
Lord Howe Island (Milky Way) 5.4 2.0 - - 0.2 1.0 0.2 - 24.8 34.6 9.8 0.2 - - - - - - - - - - - - 13.0 21.2 5.0 - - 0.6 -
Lord Howe Island Aero 4.6 2.0 - - 2.0 1.6 0.4 0.2 13.6 31.0 9.6 0.2 - 0.2 - - - - - - - - - - 11.4 35.0 3.0 - - 0.2 0.6
Norfolk Island Aero - 0.2 0.6 - - - 1.2 2.0 - - - - 3.0 21.8 - - - 1.0 - - 4.6 0.2 - - - - - 2.8 9.4 6.4 -
Antarctica and Macquarie Is. (300)12345678910111213141516171819202122232425262728293031
Casey - - - - - - - - - - - - - 4.4 1.0 0.6 - - - - - - - - - - - - - - -
Davis - - - - -

- - - - 0.6 - -
- - 0.2 - - - - - - - - - - - - -
Macquarie Island 0.4 0.6 0.6 7.8 0.8 1.4 - 3.8 2.4 1.2 4.0 0.6 0.2 - 0.4 0.4 4.6 1.8 13.6 6.6 8.8 5.4 0.4 1.2 9.4 1.8 1.0 3.4 1.2 6.2 9.0
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 10 am on Tuesday 4 January 2022. 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

Climate