Melbourne Metropolitan Area and Environs in January 2010:

Mostly dry and warm; but normal rainfall and typical overnight temperatures in eastern suburbs.

Overall, across the Melbourne metropolitan area, both overnight minimum temperatures and daytime maximum temperatures were above long-term normals, with rainfall below long-term normals. However, in the eastern suburbs, overnight temperatures and rainfall totals were near to those usually experienced.

In Melbourne city, under the influence of the heat island effect (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), overnight minimum temperatures were much warmer than those usually experienced and averaged 15.9C (departure from normal 1.6C). Daytime maximum temperatures were much warmer than those usually experienced and averaged 27.5C (departure from normal 1.6C). Total rainfall for the month was 22.6 mm, this being much less than that usually recorded (normal 47.4 mm, percentage of normal received during the past month 48%).

Some 20 kilometres northwest of the city centre, temperatures at Melbourne Airport, are more typical of the Melbourne metropolitan area. This is because, being located in a somewhat rural setting, it is away from most of the influence of the heat island effect. Here, overnight minimum temperatures were near to those usually experienced and averaged 13.9C (departure from normal 0.3C). Daytime maximum temperatures were slightly warmer than those usually experienced and averaged 27C (departure from normal 0.8C).

Some sites had their lowest January temperature on record. Some sites had their highest January daily minimum temperature on record. Melbourne's overnight (11th/12th) minimum temperature of 30.6C equalled the all-time "warmest night" record (for any month), which was set during the night of 31 January/1 February 1902.

Further information

Media
(03) 9669 4057
Enquiries

Extremes in January 2010
Hottest day 45.7 C at Avalon Airport on the 11th
Warmest days on average 28.5 C at Coldstream
Coolest days on average 22.4 C at Ferny Creek (Dunns Hill)
Coldest day 12.3 C at Ferny Creek (Dunns Hill) on the 18th
Coldest night 4.7 C at Ferny Creek (Dunns Hill) on the 17th/18th
Coolest nights on average 11.1 C at Coldstream
Warmest nights on average 15.9 C at Melbourne
Warmest night 30.6 C at Melbourne on the 11th/12th
Wettest overall 75.4 mm at Ferny Creek (Dunns Hill)
Highest wind gust 91 km/h at Coldstream on the 31st

Record highest January daily minimum temperature
Highest daily minimum
temperature
in January 2010 (C)
Previous highest
for January
Years of
record
Average for
January
Coldstream 24.4 on the 12th 24.2 on the 21st in 1997 16 11.6



Record lowest January temperature
Lowest temperature
in January 2010 (C)
Previous lowest
for January
Years of
record
Average for
January
Ferny Creek (Dunns Hill) 4.7 on the 18th 4.8 on the 18th in 2004 19 12.1



Summary statistics for January 2010
Maximum temperatures
for January
(C)
Minimum temperatures
for January
(C)
Rainfall
for January
(millimetres)
Mean for
January
2010
Diff
from
average
Highest for
January
2010
Mean for
January
2010
Diff
from
average
Lowest for
January
2010
Total for
January
2010
Average
for
January
Rank of
January
2010
Fraction of
January
average
Avalon Airport 27.0 +0.9 45.7 11th 13.6 -0.4 8.6 18th 9.2 28.7 low 32%
Bundoora (Latrobe University) 27.3 +0.9 43.6 11th 14.2 +0.2 8.9 18th 53.7 47.1 average 114%
Cerberus 24.8 +0.6 42.7 11th 13.6 -0.1 7.6 26th 28.2 36.3 average 78%
Coldstream 28.5 +0.8 42.4 11th 11.1 -0.5 4.8 24th 59.4 44.5 average 133%
Cranbourne Botanic Gardens 25.8 +0.6 43.0 11th 13.2 -0.2 8.0 24th 41.9 53.5 average 78%
Essendon Airport 27.2 +0.9 43.4 11th 14.2 +0.9 8.9 18th 30.8 43.2 average 71%
Ferny Creek (Dunns Hill) 22.4 +0.2 37.2 11th 11.4 -0.7 4.7 18th 75.4 66.0 average 114%
Laverton RAAF 26.7 +1.1 44.7 11th 14.7 +1.1 9.5 18th 21.2 39.0 average 54%
Melbourne Airport 27.0 +0.8 42.5 11th 13.9 +0.3 8.6 24th 27.2 41.3 average 66%
Melbourne Regional Office 27.5 +1.6 43.6 11th 15.9 +1.6 10.4 18th 22.6 47.4 low 48%
Moorabbin Airport 26.4 +0.8 43.9 11th 14.3 +0.2 8.8 24th 46.0 44.5 average 103%
Scoresby Research Institute 27.2 +1.1 42.1 11th 13.2 +0.1 6.9 24th 55.0 52.7 average 104%
Viewbank (ARPANSA) 27.6 -0.1 43.1 11th 13.9 -0.3 8.6 18th 71.8 37.6 highest 191%

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 Tuesday 2 February 2010. 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