Melbourne Metropolitan Area and Environs in May 2012: Rainfall more than that usually received.

Summary

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 10.0C (departure from normal 1.4C). 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 near to those usually experienced and averaged 17.0C (departure from normal 0.3C). Total rainfall for the month  was 80.0 mm (normal 56.0 mm, percentage of normal received 143%).

Selected Melbourne suburbs

In the suburb of Essendon, which is located some 15 kilometres to the northwest of the city centre, overnight minimum temperatures were slightly warmer than those usually experienced and averaged 8.4C (departure from normal 0.7C). Daytime maximum temperatures were near to those usually experienced and averaged 16C (departure from normal -0.1C). Total rainfall for the month  was 70.8 mm (normal 49.4 mm, percentage of normal received 143%).

The suburb of Laverton is located some 30 kilometres to the southwest of the city centre, and is often under the drying influence of the rain shadow from the ranges of western Victoria. Here, overnight minimum temperatures were near to those usually experienced and averaged 7.7C (departure from normal -0.1C). Daytime maximum temperatures were near to those usually experienced and averaged 16.6C (departure from normal -0.2C). Total rainfall for the month  was 67.4 mm (normal 46.8 mm, percentage of normal received 144%).

In the suburb of Bundoora, which is located some 20 kilometres to the northeast of the city centre, overnight minimum temperatures were slightly warmer than those usually experienced and averaged 8.7C (departure from normal 0.8C). Daytime maximum temperatures were slightly cooler than those usually experienced and averaged 16C (departure from normal -0.6C). Total rainfall for the month  was 86.4 mm (normal 52.2 mm, percentage of normal received 166%).

In the suburb of Moorabbin, which is located some 20 kilometres to the southeast of the city centre, overnight minimum temperatures were slightly warmer than those usually experienced and averaged 9.2C (departure from normal 0.6C). Daytime maximum temperatures were slightly cooler than those usually experienced and averaged 16.2C (departure from normal -0.7C). Total rainfall for the month  was 93.2 mm (normal 70.6 mm, percentage of normal received 132%).

Rainfall

Some sites had their highest total May rainfall on record.

Some sites had their highest total May rainfall for at least 10 years.

Further information

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Extremes in May 2012
Hottest day 24.3 C at Avalon Airport on the 9th
Warmest days on average 17.2 C at Avalon Airport
Coolest days on average 15.6 C at Cranbourne Botanic Gardens
Coldest day 10.5 C at Scoresby Research Institute on the 25th
Coldest night -1.1 C at Coldstream on the 21st
Coolest nights on average 6.0 C at Coldstream
Warmest nights on average 10.0 C at Melbourne Regional Office
Warmest night 15.5 C at Bundoora (Latrobe University) on the 9th
15.5 C at Scoresby Research Institute on the 9th
Warmest on average overall 13.5 C at Melbourne Regional Office
Coolest on average overall 10.8 C at Coldstream
Wettest overall 165.0 mm at Cerberus
Highest wind gust 72 km/h at Melbourne Airport on the 8th
72 km/h at Moorabbin Airport on the 23rd
72 km/h at Essendon Airport on the 25th
72 km/h at Melbourne Airport on the 25th

Record highest total May rainfall
Total rainfall
for May 2012 (mm)
Previous wettest
for May
Years of
record
Average for
May
Cerberus 165.0 128.0 in 2000 21 68.8

Highest total May rainfall for at least 10 years
Total rainfall
for May 2012 (mm)
Most recent May
at least this wet
Years since
wetter
Average for
May
Avalon Airport 68.6 69.4 in 1978* 25 35.7
Laverton RAAF 67.4 68.6 in 1995 17 46.8
Essendon Airport 70.8 119.5 in 1981* 15 49.4
Melbourne Airport 53.0 78.4 in 2000 12 40.4
Melbourne Regional Office 80.0 91.0 in 2000 12 56.0
Moorabbin Airport 93.2 105.2 in 2000 12 70.6
Viewbank 74.4 144.0 in 2000 12 53.1
Bundoora (Latrobe University) 86.4 122.4 in 2000* 11 52.2
Cranbourne Botanic Gardens 114.0 153.4 in 2000* 11 64.1
Scoresby Research Institute 102.8 136.4 in 2000* 11 88.7

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




Summary statistics for May 2012
Maximum temperatures
for May
(C)
Minimum temperatures
for May
(C)
Rainfall
for May
(millimetres)
Mean for
May
2012
Diff
from
average
Highest for
May
2012
Mean for
May
2012
Diff
from
average
Lowest for
May
2012
Total for
May
2012
Average
for
May
Rank of
May
2012
Fraction of
May
average
Avalon Airport 17.2 +0.2 24.3 9th 7.6 +0.1 2.7 21st 68.6 35.7 v high 192%
Bundoora (Latrobe University) 16.0 -0.6 21.8 1st 8.7 +0.8 1.1 21st 86.4 52.2 high 166%
Cerberus 15.8 -0.7 22.4 1st 9.0 +0.7 3.9 31st 165.0 68.8 highest 240%
Coldstream 15.7 -0.7 22.6 1st 6.0 +0.6 -1.1 21st 87.0 64.9 high 134%
Cranbourne Botanic Gardens 15.6 -0.7 22.0 1st 8.6 +0.2 3.6 21st 114.0 64.1 high 178%
Essendon Airport 16.0 -0.1 22.5 1st 8.4 +0.7 3.7 21st 70.8 49.4 high 143%
Laverton RAAF 16.6 -0.2 23.7 9th 7.7 -0.1 2.4 21st 67.4 46.8 high 144%
Melbourne Airport 15.7 -0.9 22.3 1st 7.7 -0.6 3.8 21st 53.0 40.4 high 131%
Melbourne Regional Office 17.0 +0.3 22.6 1st 10.0 +1.4 4.6 21st 80.0 56.0 high 143%
Moorabbin Airport 16.2 -0.7 22.6 9th 9.2 +0.6 3.3 31st 93.2 70.6 high 132%
Scoresby Research Institute 15.7 -0.5 21.4 1st 8.3 +0.1 3.3 21st 102.8 88.7 average 116%
Viewbank 16.1 -1.0 22.8 1st 8.2 +0.5 1.1 21st 74.4 53.1 high 140%

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 2 pm on Friday 1 June 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