Wednesday, 5 January 2011 - Monthly Climate Summary for Melbourne Metropolitan Area and Environs - Product code IDCKGC2xx0
Melbourne Metropolitan Area in December 2010: A humid start to summer
- Above average rainfall
- Very humid conditions in early December
- Warm nights and close to normal days
The Central district experienced another above average month for rainfall. Coldstream, Cranbourne Botanic Gardens and Scoresby Research Institute recorded rainfall totals more than double that usually received in December.
The wettest location this month was Ferny Creek (Dunns Hill), which recorded 166.0 mm, in line with its neighbours to the northeast of the region, including Coldstream and Scoresby Research Institute, where monthly totals of more than 145 mm were also reported. In contrast, some locations only received rainfall totals close to their long-term average, including Avalon Airport and Laverton RAAF, with only 26.0 mm and 55.4 mm of rainfall for the month respectively.
Heavy rainfall in the eastern half of the Central district recorded on the 20th delivered 50.0 mm to Scoresby Research Institute and 22.2 mm reported at the Melbourne Regional Office. A strong system passed across the state in the 24 hours to 9am on the 9th bringing the highest daily total for the month to several sites in the Melbourne Metropolitan region including the Melbourne Regional Office (28.8 mm), Essendon Airport (23.4 mm) and Moorabbin Airport (32.6 mm).
Maximum temperatures in the Central district in December 2010 were generally very close to the long-term average. Stations to the north of Melbourne reported average daytime temperatures slightly below the climatological average. Viewbank experienced a slightly cool start to summer with December days around 0.8 °C cooler than usual.
Melbourne Regional Office, on the other hand, reported warmer than normal days, the warmest of which was the 31st of December, a scorching 41.1 °C for New Years Eve celebrations. Across the Melbourne region, and much of Victoria, temperatures on the final day of 2010 soared well above 40 °C. Avalon Airport recorded the hottest day for the region on the 31st, a sweltering 42.8 °C.
Chilly days occurred mid-month with a cold outbreak bringing snow to parts of Victoria. Across the Melbourne region, unseasonably cool conditions were experienced, with daily maximum temperatures between the 18th and 21st restrained to below 20 °C.
Night-time temperatures were generally above average in the Melbourne Metropolitan area for December. The warmest nights were experienced at the Melbourne Regional Office, averaging 14.5 °C, more than 1.6 °C above the long-term average for this site.
Systems of tropical origin passed through the Victorian region early in the month and brought very humid conditions to Melbourne. Dewpoint temperatures reached 20.0 °C on several occasions in the first weeks of the month, a very rare occurrence for Melbourne in December. The warmest night was the 8th, with a balmy minimum of 22.6 °C recorded at the Melbourne Regional Office.
The 22nd and 28th were the coolest nights in the Melbourne Metropolitan area, with temperatures dropping to just 4.3 °C at Coldstream on the 28th and below 6 °C in surrounding areas. Ferny Creek (Dunns Hill) experienced the coolest nights for the region, averaging 10.2 °C, equal to the long-term average at this site.
|Extremes in December 2010|
|Hottest day||42.8 °C at Avalon Airport on the 31st|
|Warmest days on average||24.9 °C at Bundoora (Latrobe University)|
|Coolest days on average||19.6 °C at Ferny Creek (Dunns Hill)|
|Coldest day||10.9 °C at Ferny Creek (Dunns Hill) on the 21st|
|Coldest night||4.3 °C at Coldstream on the 28th|
|Coolest nights on average||10.2 °C at Ferny Creek (Dunns Hill)|
|Warmest nights on average||14.5 °C at Melbourne Regional Office|
|Warmest night||22.6 °C at Melbourne Regional Office on the 8th|
|Warmest on average overall||19.6 °C at Melbourne Regional Office|
|Coolest on average overall||14.9 °C at Ferny Creek (Dunns Hill)|
|Wettest overall||166.0 mm at Ferny Creek (Dunns Hill)|
|Driest overall||26.0 mm at Avalon Airport|
|Wettest day||50.0 mm at Scoresby Research Institute on the 20th|
|Highest wind gust||94 km/h at Avalon Airport on the 3rd|
|Summary statistics for December 2010|
|East Central (district 86)|
|Bundoora (Latrobe University)||24.9||+0.2||40.8||31st||12.5||+0.2||5.5||28th||76.0||64.2||average||118%|
|Cranbourne Botanic Gardens||22.9||-0.4||38.9||31st||11.7||0.0||6.5||24th||133.4||64.9||v high||206%|
|Ferny Creek (Dunns Hill)||19.6||-0.3||34.2||31st||10.2||0.0||5.3||28th||166.0||88.8||high||187%|
|Melbourne Regional Office||24.8||+0.6||41.1||31st||14.5||+1.6||9.0||28th||85.2||59.3||high||144%|
|Moorabbin Airport||23.5||-0.3||40.2||31st||13.1||+0.6||7.8||28th||111.2||59.6||v high||187%|
|Scoresby Research Institute||23.9||0.0||39.6||31st||12.1||+0.3||5.1||28th||153.2||76.6||v high||200%|
|West Central (district 87)|
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 Wednesday 5 January 2011. 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
(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.