Melbourne Metropolitan Area and Environs in December 2012:

Rainfall less than that usually received.

    Located in the Central District at the head of Port Phillip Bay, Melbourne is Victoria's State Capital. Here, overnight minimum temperatures were much warmer than those usually experienced and averaged 15.1C (departure from normal 2.2C). That the overnight temperatures in Melbourne are higher than those in most surrounding localities is a consequence of the city being under the influence of the effect of urbanisation (cities are usually warmer than their rural surroundings, especially at night, because of heat stored in bricks and concrete and trapped between close-packed buildings). Daytime maximum temperatures were much warmer than those usually experienced and averaged 25.7C (departure from normal 1.5C). Total rainfall for the month was 30 mm, this being less than that usually recorded (normal 59.3 mm, percentage of normal received 51%).

    Some 20 kilometres northwest of the Melbourne city centre, and located in a somewhat rural setting, Melbourne Airport, is more typical of the suburban areas of Melbourne. Here, overnight minimum temperatures were slightly warmer than those usually experienced and averaged 12.5C (departure from normal 0.5C). Daytime maximum temperatures were much warmer than those usually experienced and averaged 26C (departure from normal 1.6C). Total rainfall for the month was 18.6 mm, this being much less than that usually recorded (normal 48.8 mm, percentage of normal received 38%).

Minimum temperature

Some sites had their warmest December night (highest daily minimum temperature) on record.

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Extremes in December 2012
Hottest day 39.2 C at Melbourne Airport on the 23rd
Warmest days on average 26.4 C at Viewbank
Coolest days on average 23.2 C at Cerberus
Coldest day 16.0 C at Cranbourne Botanic Gardens on the 4th
Coldest night 4.5 C at Coldstream on the 30th
Coolest nights on average 10.1 C at Coldstream
Warmest nights on average 15.1 C at Melbourne Regional Office
Warmest night

27.4 C at Melbourne Regional Office on the 24th

Warmest on average overall 20.4 C at Melbourne Regional Office
Coolest on average overall 17.5 C at Cerberus
Wettest overall 57.3 mm at Cranbourne Botanic Gardens
Highest wind gust 93 km/h at Melbourne Airport on the 24th

Record highest December daily minimum temperature
Highest daily minimum
temperature
in December 2012 (C)
Previous warmest
for December
Years of
record
Average for
December
Laverton RAAF 26.0 on the 24th = 26.0 on the 7th in 1994 70 11.9
Melbourne Regional Office 27.4 on the 24th 27.2 on the 28th in 1961 158 12.9
Essendon Airport 25.9 on the 24th 24.9 on the 4th in 1970 43 11.7
Viewbank 23.8 on the 24th 22.8 on the 10th in 2003 14 12.4



Summary statistics for December 2012
Maximum temperatures
for December
(C)
Minimum temperatures
for December
(C)
Rainfall
for December
(millimetres)
Mean for
December
2012
Diff
from
average
Highest for
December
2012
Mean for
December
2012
Diff
from
average
Lowest for
December
2012
Total for
December
2012
Average
for
December
Rank of
December
2012
Fraction of
December
average
East Central (district 86)
Bundoora (Latrobe University) 25.7 +1.0 38.9 23rd 13.0 +0.7 8.3 22nd 25.7 64.8 low 40%
Cerberus 23.2 +1.0 37.3 23rd 11.8 0.0 6.1 22nd 52.8 52.7 average 100%
Coldstream 25.4 +0.5 37.2 23rd 10.1 +0.6 4.5 30th 34.0 54.9 low 62%
Cranbourne Botanic Gardens 24.9 +1.6 37.5 23rd 11.4 -0.3 6.8 22nd 57.3 65.5 average 87%
Essendon Airport 26.1 +1.8 39.0 23rd 13.3 +1.6 8.7 17th 18.0 51.4 low 35%
Melbourne Airport 26.0 +1.6 39.2 23rd 12.5 +0.5 7.7 17th 18.6 48.8 low 38%
Melbourne Regional Office 25.7 +1.5 38.3 23rd 15.1 +2.2 11.8 17th 30.0 59.3 low 51%
Moorabbin Airport 24.8 +1.0 37.9 23rd 13.2 +0.7 8.2 10th 36.8 59.1 low 62%
Scoresby Research Institute 25.5 +1.6 38.5 23rd 12.3 +0.5 7.1 10th 40.6 76.0 low 53%
Viewbank 26.4 +1.1 39.0 23rd 13.0 +0.6 8.3 22nd 21.8 68.6 v low 32%
West Central (district 87)
Avalon Airport 25.5 +1.5 38.8 23rd 11.9 +0.3 7.1 22nd 32.4 29.6 average 109%
Laverton RAAF 25.0 +1.3 38.6 23rd 12.8 +0.9 7.0 17th 29.8 46.0 average 65%

Notes

A Monthly Climate Summary is prepared to list the main features of the weather in Melbourne Metropolitan Area and Environs using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.

This statement has been prepared based on information available at 10 am on Thursday 3 January 2013. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Averages 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 rain.

The Rank indicates how rainfall this time compares with the climate record for the site, based on the decile ranking (very low rainfall 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 rain has fallen this time as a percentage of the long-term mean.

Further information

Media
(03) 9669 4057
Enquiries