Melbourne Metropolitan Area and Environs in October 2012: Rainfall much 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 warmer than those usually experienced and averaged 10.8C (departure from normal 1.3C). 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 warmer than those usually experienced and averaged 20.8C (departure from normal 1.1C). Total rainfall for the month was 29 mm, this being much less than that usually recorded (normal 66.1 mm, percentage of normal received 44%).

Some 20 kilometres northwest of the Melbourne city centre, and typical of the suburbs, is Melbourne Airport. Here, overnight minimum temperatures were near to those usually experienced and averaged 8C (departure from normal -0.5C). Nights were more than 2C cooler than in the city. Daytime maximum temperatures were warmer than those usually experienced and averaged 20.3C (departure from normal 1.1C). Total rainfall for the month thus far was 24.4 mm, this being much less than that usually recorded (normal 54.7 mm, percentage of normal received 45%).

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Extremes in October 2012
Hottest day 33.5 C at Laverton RAAF on the 31st
Warmest days on average 20.8 C at Melbourne Regional Office
Coolest days on average 18.9 C at Cerberus
Coldest day 11.7 C at Melbourne Airport on the 11th
Coldest night 2.6 C at Coldstream on the 23rd
Coolest nights on average 6.9 C at Coldstream
Warmest nights on average 10.8 C at Melbourne Regional Office
Warmest night 18.6 C at Melbourne Regional Office on the 31st
Warmest on average overall 15.8 C at Melbourne Regional Office
Coolest on average overall 13.4 C at Coldstream
Wettest overall 49.8 mm at Coldstream
Highest wind gust 80 km/h at Essendon Airport on the 16th
80 km/h at Laverton RAAF on the 16th

Summary statistics for October 2012
Maximum temperatures
for October
(C)
Minimum temperatures
for October
(C)
Rainfall
for October
(millimetres)
Mean for
October
2012
Diff
from
average
Highest for
October
2012
Mean for
October
2012
Diff
from
average
Lowest for
October
2012
Total for
October
2012
Average
for
October
Rank of
October
2012
Fraction of
October
average
Avalon Airport 20.0 +0.2 33.2 31st 7.3 -0.6 2.7 14th 24.6 50.1 low 49%
Bundoora (Latrobe University) 20.4 +0.9 31.6 30th 8.5 -0.1 4.2 7th 33.1 64.7 low 51%
Cerberus 18.9 +0.6 30.6 31st 8.4 -0.3 4.4 9th 40.2 68.3 low 59%
Coldstream 19.9 +0.5 29.4 30th 6.9 +0.4 2.6 23rd 49.8 66.6 average 75%
Cranbourne Botanic Gardens 19.5 +0.7 30.6 31st 8.6 -0.2 4.5 9th 44.0 78.5 low 56%
Essendon Airport 20.5 +1.4 32.2 30th 8.7 +0.6 4.4 9th 18.6 60.6 low 31%
Laverton RAAF 20.2 +1.0 33.5 31st 7.8 -0.4 3.3 7th 20.0 56.9 v low 35%
Melbourne Airport 20.3 +1.1 31.2 30th 8.0 -0.5 3.7 9th 24.4 54.7 low 45%
Melbourne Regional Office 20.8 +1.1 32.0 30th 10.8 +1.3 6.8 7th 29.0 66.1 low 44%
Moorabbin Airport 19.5 +0.4 30.3 31st 9.7 +0.5 5.0 9th 26.6 70.4 v low 38%
Scoresby Research Institute 19.9 +0.9 30.6 30th 8.6 -0.2 3.5 9th 46.0 85.1 low 54%
Viewbank 20.5 +0.4 31.3 30th 8.7 -0.1 4.5 23rd 32.4 65.4 average 50%

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 3 pm on Thursday 1 November 2012. 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